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Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Assets and Liabilities

The following table presents Mattel’s derivative assets and liabilities:



	Derivative Assets
	Balance Sheet Classification	Fair Value
		December 31, 2019		December 31, 2018
		(In thousands)
Derivatives designated as hedging instruments:
Foreign currency forward exchange contracts	Prepaid expenses and other current assets	$	10,227	$	12,122
Foreign currency forward exchange contracts	Other noncurrent assets	715		1,613
		$	10,942	$	13,735
Derivatives not designated as hedging instruments:
Foreign currency forward exchange contracts	Prepaid expenses and other current assets	$	4,060	$	2,357
		$	15,002	$	16,092

	Derivative Liabilities
	Balance Sheet Classification	Fair Value
		December 31, 2019		December 31, 2018
		(In thousands)
Derivatives designated as hedging instruments:
Foreign currency forward exchange contracts	Accrued liabilities	$	2,500	$	954
Foreign currency forward exchange contracts	Other noncurrent liabilities	213		185
		$	2,713	$	1,139
Derivatives not designated as hedging instruments:
Foreign currency forward exchange contracts	Accrued liabilities	$	263	$	1,771
		$	2,976	$	2,910

Schedule of Derivatives Designated as Hedging Instruments by Classification and Amount of Gains and Losses

The following tables present the classification and amount of gains and losses, net of tax, from derivatives reported in the consolidated statements of operations:



	Derivatives Designated As Hedging Instruments								Consolidated Statements of Operations Classification
	For the Year Ended
	December 31, 2019		December 31, 2018			December 31, 2017
	(In thousands)
Foreign currency forward exchange contracts:
Amount of gains (losses) recognized in OCI	$	17,024	$	24,082		$	(55,377	)
Amount of gains (losses) reclassified from accumulated OCI to the consolidated statements of operations	17,394		(8,427		)	(16,810		)	Cost of sales

Schedule of Derivatives Not Designated as Hedging Instruments by Classification and Amount of Gains and Losses



	Derivatives Not Designated As Hedging Instruments							Consolidated Statements of Operations Classification
	For the Year Ended
	December 31, 2019		December 31, 2018			December 31, 2017
	(In thousands)
Amount of gain (loss) recognized in the consolidated statements of operations:
Foreign currency forward exchange contracts	$	2,530	$	(23,109	)	$	70,200	Other non-operating expense, net
Foreign currency forward exchange contracts	—		(244		)	511		Cost of sales
	$	2,530	$	(23,353	)	$	70,711

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current Assets
Cash and equivalents	$ 630,028	$ 594,481
Accounts receivable, net of allowances of $18.5 million and $22.0 million in 2019 and 2018, respectively	936,359	970,083
Inventories	495,504	542,889
Prepaid expenses and other current assets	186,083	239,747
Total current assets	2,247,974	2,347,200
Noncurrent Assets
Property, plant, and equipment, net	550,139	657,595
Right-of-use assets, net	303,187
Goodwill	1,390,714	1,386,424
Other noncurrent assets	833,212	847,006
Total Assets	5,325,226	5,238,225
Current Liabilities
Short-term borrowings	0	4,176
Accounts payable	459,357	537,965
Accrued liabilities	769,513	694,271
Income taxes payable	48,037	13,520
Total current liabilities	1,276,907	1,249,932
Noncurrent Liabilities
Long-term debt	2,846,751	2,851,723
Noncurrent lease liabilities	270,853
Other noncurrent liabilities	439,001	469,669
Total noncurrent liabilities	3,556,605	3,321,392
Commitments and Contingencies (See Note 12)
Stockholders’ Equity
Common stock $1.00 par value, 1.0 billion shares authorized; 441.4 million shares issued	441,369	441,369
Additional paid-in capital	1,825,569	1,812,682
Treasury stock at cost: 94.6 million shares and 96.1 million shares in 2019 and 2018, respectively	(2,318,921)	(2,354,617)
Retained earnings	1,413,181	1,626,693
Accumulated other comprehensive loss	(869,484)	(859,226)
Total stockholders’ equity	491,714	666,901
Total Liabilities and Stockholders’ Equity	$ 5,325,226	$ 5,238,225

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Loss	$ (213,512)	$ (533,299)	$ (1,054,579)
Other Comprehensive (Loss) Income, Net of Tax
Currency translation adjustments	18,919	(106,651)	191,267
Defined benefit pension plan adjustments	(27,094)	450	14,491
Net unrealized losses on available-for-sale security	(1,713)	(3,748)	(5,948)
Net unrealized (losses) gains on derivative instruments:
Unrealized holding gains (losses)	17,024
Amounts reclassified from accumulated other comprehensive loss	(17,394)
Net unrealized gains (losses) on derivative instruments	(370)
Unrealized holding gains (losses)		24,082	(55,377)
Amounts reclassified from accumulated other comprehensive loss		8,427	16,810
Net unrealized gains (losses) on derivative instruments		32,509	(38,567)
Other Comprehensive (Loss) Income, Net of Tax	(10,258)	(77,440)	161,243
Comprehensive Loss	$ (223,770)	$ (610,739)	$ (893,336)

Employee Benefit Plans - Summary of Retirement Plan Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	$ 51,332	$ 42,937	$ 56,914
Defined benefit pension plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	9,815	12,366	7,428
Defined contribution retirement plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	32,743	35,318	38,508
Postretirement benefit plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	(2,220)	(2,148)	963
Deferred compensation and excess benefit plans
Schedule of Employee Benefit Plans [Line Items]
Retirement plan expense	$ 10,994	$ (2,599)	$ 10,015

Share-Based Payments - Weighted Average Assumptions Used to Determine Fair Value of Options Granted (Detail) - Stock Options	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (in years)	5 years 6 months	5 years 1 month 6 days	5 years
Risk-free interest rate	1.70%	2.80%	1.80%
Volatility factor	38.10%	33.60%	27.20%
Dividend yield	0.00%	0.00%	4.00%

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation and Basis of Preparation The consolidated financial statements include the accounts of Mattel, Inc. and its subsidiaries. All wholly and majority-owned subsidiaries are consolidated and included in Mattel’s consolidated financial statements. Mattel does not have any minority stock ownership interests in which it has a controlling financial interest that would require consolidation. All significant intercompany accounts and transactions have been eliminated upon consolidation. On January 1, 2018, Mattel adopted Accounting Standards Update ("ASU") 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. As a result, other selling and administrative expenses, operating income (loss), and other non-operating expense, net have been retrospectively restated. The impact to Mattel’s consolidated financial statements was not material. See further discussion in "Note 1 to the Consolidated Financial Statements—Summary of Significant Accounting Policies—New Accounting Pronouncements" and "Note 4 to the Consolidated Financial Statements—Employee Benefit Plans." Revision of Consolidated Financial Statements Mattel’s consolidated financial statements have been revised to correct for the overstatement of accrued royalties payable and understatement of retained earnings of $10.1 million as of January 1, 2015 and all subsequent periods presented. Mattel concluded that the prior period misstatement was not material, both individually or in the aggregate, to previously issued consolidated financial statements. Use of Estimates Preparation of the consolidated financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could ultimately differ from those estimates. Cash and Equivalents Cash and equivalents include short-term investments, which are highly liquid investments with maturities of three months or less when purchased. Such investments are stated at cost, which approximates market value. Accounts Receivable and Allowance for Doubtful Accounts Credit is granted to customers on an unsecured basis. Credit limits and payment terms are established based on extensive evaluations made on an ongoing basis throughout the fiscal year of the financial performance, cash generation, financing availability, and liquidity status of each customer. Customers are reviewed at least annually, with more frequent reviews performed as necessary, based on the customers’ financial condition and the level of credit being extended. For customers who are experiencing financial difficulties, management performs additional financial analyses before shipping to those customers on credit. Mattel uses a variety of financial arrangements to ensure collectibility of accounts receivable of customers deemed to be a credit risk, including requiring letters of credit, purchasing various forms of credit insurance with unrelated third parties, factoring, or requiring cash in advance of shipment. Mattel records an allowance for doubtful accounts based on management’s assessment of the business environment, customers’ financial condition, historical collection experience, accounts receivable aging, and customer disputes. Inventories Inventories, net of allowance for obsolescence, are stated at the lower of cost or net realizable value. Expense associated with the allowance for obsolescence is recognized in cost of sales and establishes a lower cost basis for the inventory. Cost is determined by the first-in, first-out method. Property, Plant, and Equipment Property, plant, and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over estimated useful lives of 10 to 30 years for buildings, 3 to 15 years for machinery and equipment, 3 to 10 years for software, and 10 to 20 years, not to exceed the lease term, for leasehold improvements. Tools, dies, and molds are depreciated using the straight-line method over 3 years. Estimated useful lives are periodically reviewed and, where appropriate, changes are made prospectively. The carrying value of property, plant, and equipment is reviewed when events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. Any potential impairment identified is initially assessed by evaluating the operating performance and future undiscounted cash flows of the underlying assets. When property is sold or retired, the cost of the property and the related accumulated depreciation are removed from the consolidated balance sheets, and any resulting gain or loss is included in the consolidated statements of operations. Goodwill and Intangible Assets Goodwill is allocated to various reporting units, which are at the operating segment level, for the purpose of evaluating whether goodwill is impaired. Mattel’s reporting units are: (i) North America, (ii) International, and (iii) American Girl. Components of the operating segments have been aggregated into a single reporting unit as the components have similar economic characteristics. The similar economic characteristics include the nature of the products, the nature of the production processes, the customers, and the manner in which the products are distributed. Mattel tests its goodwill for impairment annually in the third quarter and whenever events or changes in circumstances indicate that the carrying value of a reporting unit may exceed its fair value. Mattel had no indefinite-lived intangible assets as of and for the years ended December 31, 2019 and December 31, 2018. Prior to 2018, Mattel tested indefinite-lived intangible assets for impairment annually in the third quarter or whenever events or changes in circumstances indicated that the carrying value may have exceeded its fair value. Mattel also tests its amortizable intangible assets, which are primarily comprised of trademarks and trade names, for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be recovered. Amortization is computed primarily using the straight-line method over the estimated useful lives of the amortizable intangible assets. Foreign Currency Translation Exposure Mattel’s reporting currency is the U.S. dollar. The translation of its net investments in subsidiaries with non-U.S. dollar functional currencies subjects Mattel to the impact of currency exchange rate fluctuations in its results of operations and financial position. Assets and liabilities of subsidiaries with non-U.S. dollar functional currencies are translated into U.S. dollars at year-end exchange rates. Net income (loss) and cash flow items are translated at weighted-average exchange rates prevailing during the year. The resulting currency translation adjustments are recorded as a component of accumulated other comprehensive loss within stockholders’ equity. Mattel’s primary currency translation exposures in 2019 were related to its net investments in entities having functional currencies denominated in the Euro, British pound sterling, Russian ruble, and Mexican peso. Foreign Currency Transaction Exposure Currency exchange rate fluctuations may impact Mattel’s results of operations and cash flows. Mattel’s currency transaction exposures include gains and losses realized on unhedged inventory purchases and unhedged receivables and payables balances that are denominated in a currency other than the applicable functional currency. Gains and losses on unhedged inventory purchases and other transactions associated with operating activities are recorded in the components of operating income (loss) in the consolidated statements of operations. Gains and losses on unhedged intercompany loans and advances are recorded as a component of other non-operating expense, net in the consolidated statements of operations in the period in which the currency exchange rate changes. Inventory transactions denominated in the Euro, Mexican peso, British pound sterling, Canadian dollar, Russian ruble, Brazilian real, and Australian dollar were the primary transactions that caused foreign currency transaction exposure for Mattel in 2019. Derivative Instruments Mattel uses foreign currency forward exchange contracts as cash flow hedges primarily to hedge its purchases and sales of inventory denominated in foreign currencies. At the inception of the contracts, Mattel designates these derivatives as cash flow hedges and documents the relationship of the hedge to the underlying transaction. Hedge effectiveness is assessed at inception and throughout the life of the hedge to ensure the hedge qualifies for hedge accounting. Changes in fair value associated with hedge ineffectiveness, if any, are recorded in the consolidated statements of operations. Changes in fair value of cash flow hedge derivatives are deferred and recorded as part of accumulated other comprehensive loss in stockholders’ equity until the underlying transaction affects earnings. In the event that an anticipated transaction is no longer likely to occur, Mattel recognizes the change in fair value of the derivative in its consolidated statements of operations in the period the determination is made. Additionally, Mattel uses foreign currency forward exchange contracts to hedge intercompany loans and advances denominated in foreign currencies. Due to the short-term nature of the contracts involved, Mattel does not use hedge accounting for these contracts, and as such, changes in fair value are recorded in the period of change in the consolidated statements of operations. Revenue Recognition and Sales Adjustments Revenue is recognized when control of the goods is transferred to the customer, which is either upon shipment or upon receipt of finished goods by the customer, depending on the contract terms. Mattel routinely enters into arrangements with its customers to provide sales incentives, support customer promotions, and provide allowances for returns or defective merchandise. Such programs are based primarily on customer purchases, customer performance of specified promotional activities, and other specified factors such as sales to consumers. Accruals for these programs are recorded as sales adjustments that reduce gross sales in the period the related sale is recognized. The accrual for such programs, which can either be contractual or discretionary in nature, is based on an assessment of customer purchases, customer performance of specified promotional activities, and other specified factors such as customer sales volume. In making these estimates, management considers all available information, including the overall business environment, historical trends, and information from customers. Mattel also enters into symbolic and functional licensing arrangements, whereby the licensee pays Mattel royalties based on sales of licensed product, and in certain cases are subject to minimum guaranteed amounts. The timing of revenue recognition for certain of these licensing arrangements with minimum guarantees changed under the new revenue recognition standards, which under the new revenue recognition standards is based on the determination of whether the license of intellectual property ("IP") is symbolic, which includes the license of Mattel's brands, or functional, which includes the license of Mattel's completed television or streaming content. Revenues from symbolic licenses of IP are recognized based on actual sales when Mattel expects royalties to exceed the minimum guarantee. For symbolic licensing arrangements in which Mattel does not expect royalties to exceed the minimum guarantee, an estimate of the royalties expected to be recouped is recognized on a straight-line basis over the license term. Revenues from functional licenses of IP are recognized once the license period has commenced and the licensee has the ability to use the delivered content. Mattel applied the practical expedient prescribed in the new revenue recognition standards and did not evaluate contracts of one year or less for the existence of a significant financing component. Multi-year contracts were not material. Advertising and Promotion Costs Costs of media advertising, including direct-response advertising, are capitalized and expensed the first time the advertising takes place. Product Recalls and Withdrawals Mattel establishes a reserve for product recalls and withdrawals on a product-specific basis when circumstances giving rise to the recall or withdrawal become known. Facts and circumstances related to the recall or withdrawal, including where the product affected by the recall or withdrawal is located (e.g., with consumers, in customers’ inventory, or in Mattel’s inventory), cost estimates for shipping and handling for returns, cost estimates for communicating the recall or withdrawal to consumers and customers, and cost estimates for parts and labor if the recalled or withdrawn product is deemed to be repairable, are considered when establishing a product recall or withdrawal reserve. These factors are updated and reevaluated each period, and the related reserves are adjusted when these factors indicate that the recall or withdrawal reserve is either not sufficient to cover or exceeds the estimated product recall or withdrawal expenses. Design and Development Costs Product design and development costs primarily include employee compensation and outside services and are charged to the results of operations as incurred. Employee Benefit Plans Mattel and certain of its subsidiaries have retirement and other postretirement benefit plans covering substantially all employees of these entities. Actuarial valuations are used in determining amounts recognized in the financial statements for certain retirement and other postretirement benefit plans (see "Note 4 to the Consolidated Financial Statements—Employee Benefit Plans"). Share-Based Payments Mattel recognizes the cost of service-based employee share-based payment awards on a straight-line attribution basis over the requisite employee service period, net of estimated forfeitures. Determining the fair value of share-based awards at the measurement date requires judgment, including estimating the expected term that stock options will be outstanding prior to exercise, the associated volatility, and the expected dividends. With the exception of certain market-based options granted in 2018, which are valued using a Monte Carlo valuation methodology, Mattel estimates the fair value of options granted using the Black-Scholes valuation model. The expected life of the options used in this calculation is the period of time the options are expected to be outstanding and has been determined based on historical exercise experience. Expected stock price volatility is based on the historical volatility of Mattel’s stock for a period approximating the expected life, the expected dividend yield is based on Mattel’s most recent actual annual dividend payout, and the risk-free interest rate is based on the implied yield available on U.S. Treasury zero-coupon issues approximating the expected life. Judgment is also required in estimating the amount of share-based awards that will be forfeited prior to vesting. Mattel determines the fair value of RSUs, excluding performance RSUs, based on the closing market price of Mattel’s common stock on the date of grant, adjusted by the present value of the expected dividends for RSUs that are not entitled to a dividend during the vest period. Mattel determines the fair value of the performance-related components of its performance RSUs based on the closing market price of Mattel's common stock on the date of grant. It determines the fair value of the market-related components of its performance RSUs based on a Monte Carlo valuation methodology. Income Taxes Certain income and expense items are accounted for differently for financial reporting and income tax purposes. Deferred income tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities, applying enacted statutory income tax rates in effect for the year in which the differences are expected to reverse. Mattel evaluates the realization of our deferred tax assets based on all available evidence and establishes a valuation allowance to reduce deferred tax assets when it is more likely than not that they will not be realized. Mattel recognizes the financial statement effects of a tax position when it is more likely than not that, based on technical merits, the position will be sustained upon examination. The tax benefits of the position recognized in the financial statements are then measured based on the largest amount of benefit that is greater than 50% likely to be realized upon settlement with a taxing authority. In addition, we recognize interest and penalties related to unrecognized tax benefits as a component of the income tax provision. In the normal course of business, Mattel is regularly audited by federal, state, local, and foreign tax authorities. The ultimate settlement of any particular issue with the applicable taxing authority could have a material impact on Mattel’s consolidated financial statements. Venezuelan Operations Since January 1, 2010, Mattel has accounted for Venezuela as a highly inflationary economy as the three-year cumulative inflation rate for Venezuela exceeded 100%. Accordingly, Mattel’s Venezuelan subsidiary used the U.S. dollar as its functional currency, and monetary assets and liabilities denominated in Venezuelan bolívar fuerte ("BsF") generated income or expense for changes in value associated with foreign currency exchange rate fluctuations against the U.S. dollar. During December 2017, Mattel initiated actions to discontinue operations in Venezuela and concluded that its Venezuelan subsidiary had been substantially liquidated. In connection with the substantial liquidation, Mattel recognized a $59.0 million loss in other non-operating expense, net in the consolidated statements of operations related to the associated cumulative translation adjustments. Argentina Operations Effective July 1, 2018, Mattel accounted for Argentina as a highly inflationary economy, as the projected three-year cumulative inflation rate exceeded 100%. As such, beginning July 1, 2018, Mattel's Argentina subsidiary has designated the U.S. dollar as its functional currency. Mattel’s Argentina subsidiary represented less than 1% of Mattel's consolidated net sales for the years ended December 31, 2019 and 2018. New Accounting Pronouncements Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Board ("FASB") issued ASU 2016-02, Leases (Topic 842), as amended. Mattel adopted the new lease standard on January 1, 2019 using the modified retrospective transition method. Prior periods were not retrospectively adjusted and continue to be reported under the accounting standards in effect for those periods, as further discussed in "Note 7 to the Consolidated Financial Statements—Leases." In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities, which expands the hedging strategies eligible for hedge accounting and changes both how companies assess hedge effectiveness and presentation and disclosure requirements. Mattel adopted ASU 2017-12 on January 1, 2019 and the adoption did not have a material impact on its consolidated financial statements. In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits the reclassification of disproportionate tax effects in accumulated other comprehensive income (loss) caused by the U.S. Tax Act to retained earnings. Mattel adopted ASU 2018-02 on January 1, 2019 and the adoption did not have a material impact on its consolidated financial statements. For additional information, see "Note 15 to the Consolidated Financial Statements—Income Taxes." Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), which changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. This update replaces the existing incurred loss impairment model with an expected loss model (referred to as the Current Expected Credit Loss model, or "CECL"). In November 2018, the FASB issued ASU 2018-19, Codifications Improvements to Topic 326, Financial Instruments-Credit Losses" which clarifies that receivables arising from operating leases are accounted for using lease guidance and not as financial instruments. ASU 2016-13 and its related amendments (ASU 2018-19, ASU 2019-04, ASU 2019-05, ASU 2019-10, and ASU 2019-11) will become effective for the fiscal year beginning on January 1, 2020. During the fourth quarter of 2019, Mattel substantially completed its assessment of the impact of ASU 2016-13 and its related amendments on its consolidated financial statements and does not believe it will have a material impact on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which modifies the disclosure requirements on fair value measurements, including the consideration of costs and benefits. ASU 2018-13 will become effective for interim and annual reporting periods beginning on January 1, 2020. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty will be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments will be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. In addition, early adoption of any removed or modified disclosures, but delayed adoption of any additional disclosures until their effective date, is permitted. Mattel will adopt ASU 2018-13 on January 1, 2020 and does not expect the adoption to have a material impact on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans, which modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. ASU 2018-14 will become effective for the fiscal year beginning on January 1, 2021. Early adoption is permitted and the amendments will be applied on a retrospective basis to all periods presented. Mattel is currently evaluating the impact of the adoption of ASU 2018-14 on its consolidated financial statements. In March 2019, the FASB issued ASU 2019-02, Entertainment - Films - Other Assets - Film Costs (Subtopic 926-20): Improvements to Accounting for Costs of Films and License Agreements for Program Materials, which aligns the accounting for production costs of episodic television series with the accounting of films by removing the content distinction for capitalization. ASU 2019-02 will become effective for the fiscal year beginning on January 1, 2020. Mattel will adopt ASU 2019-02 on January 1, 2020 and does not expect the adoption to have a material impact on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which simplifies the accounting for incomes taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify the accounting for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 will become effective for the fiscal year beginning on January 1, 2021. Early adoption is permitted. The amendments related to changes in ownership of foreign equity method investments or foreign subsidiaries will be applied on a modified retrospective basis through a cumulative effect adjustment to retained earnings as of January 1, 2007. The amendments related to franchise taxes that are partially based on income will be applied on either a retrospective basis for all periods presented or a modified retrospective basis through a cumulative effect adjustment to retained earnings as of January 1, 2007. All other amendments will be applied on a prospective basis. Mattel is currently evaluating the impact of the adoption of ASU 2019-12 on its consolidated financial statements.

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Renewal term	10 years
Right-of-use assets, net	$ 303,187
Total lease liabilities, net	344,918
Operating lease, cost	142,100
Short-term and variable lease cost	44,000
Rental expense		$ 127,100	$ 137,400
Sublease income	$ 5,700	$ 3,000	$ 2,900
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	13 years
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Right-of-use assets, net				$ 343,000
Total lease liabilities, net				$ 390,000

Derivative Instruments - Schedule of Derivative Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 15,002	$ 16,092
Derivative Liabilities	2,976	2,910
Designated As Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	10,942	13,735
Derivative Liabilities	2,713	1,139
Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	10,227	12,122
Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Other noncurrent assets
Derivatives, Fair Value [Line Items]
Derivative Assets	715	1,613
Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	2,500	954
Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Other noncurrent liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	213	185
Not Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	4,060	2,357
Not Designated As Hedging Instrument \| Foreign currency forward exchange contracts \| Accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 263	$ 1,771

Goodwill and Other Intangibles - Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,386,424	$ 1,396,669
Dispositions		(4,018)
Currency exchange rate impact	4,290	(6,227)
Goodwill, ending balance	1,390,714	1,386,424
North America
Goodwill [Roll Forward]
Goodwill, beginning balance	731,234	733,034
Dispositions		0
Currency exchange rate impact	1,196	(1,800)
Goodwill, ending balance	732,430	731,234
International
Goodwill [Roll Forward]
Goodwill, beginning balance	447,619	452,152
Dispositions		0
Currency exchange rate impact	3,094	(4,533)
Goodwill, ending balance	450,713	447,619
American Girl
Goodwill [Roll Forward]
Goodwill, beginning balance	207,571	211,483
Dispositions		(4,018)
Currency exchange rate impact	0	106
Goodwill, ending balance	$ 207,571	$ 207,571

Share-Based Payments

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Share-Based Payments

Mattel Stock Option Plans

The 2010 Equity and Long-Term Compensation Plan was approved by Mattel's stockholders in May 2010 (the "2010 Plan"). Upon approval of the 2010 Plan, Mattel terminated its 2005 Equity Compensation Plan (the "2005 Plan"), except with respect to grants then outstanding under the 2005 Plan. All restricted stock unit ("RSU") awards made under the 2005 Plan have vested. Outstanding stock option grants under the 2005 Plan that have not expired or have not been terminated continue to be exercisable under the terms of their respective grant agreements. In May 2015, Mattel’s stockholders approved the Amended 2010 Plan. The terms of the Amended 2010 Plan are substantially similar to the terms of the 2010 Plan and the 2005 Plan.

Under the Amended 2010 Plan, Mattel has the ability to grant nonqualified stock options, incentive stock options, stock appreciation rights, restricted stock, RSUs, dividend equivalent rights, performance awards, and shares of common stock to officers, employees, and other persons providing services to Mattel. Generally, options vest and become exercisable contingent upon the grantees’ continued employment or service with Mattel. Nonqualified stock options are granted at not less than 100% of the fair market value of Mattel’s common stock on the date of grant, expire no later than 10 years from the date of grant, and vest on a schedule determined by the Compensation Committee of the Board of Directors, generally during a period of 3 years from the date of grant. In the event of a retirement of an employee aged 55 years or older with 5 or more years of service, or the death or disability of an employee, that occurs in each case at least 6 months after the grant date, nonqualified stock options become fully vested. Time-vesting RSUs granted under the Amended 2010 Plan generally vest over a period of 3 years from the date of grant. In the event of the involuntary termination of an employee aged 55 years or older with 5 or more years of service, or the death or disability of an employee, that occurs at least 6 months after the grant date, RSUs become fully vested. The Amended 2010 Plan also contains provisions regarding grants of equity compensation to the non-employee members of the Board of Directors. The Amended 2010 Plan expires on March 26, 2025, except as to any grants then outstanding.

The number of shares of common stock available for grant under the Amended 2010 Plan is subject to an aggregate limit of the sum of (i) 104 million shares, (ii) the number of shares that remained available for issuance under the 2005 Plan on May 12, 2010, and (iii) any shares subject to awards outstanding under the 2005 Plan that on or after May 12, 2010 are forfeited or otherwise terminate or expire without the issuance of shares to the holder of the award. The Amended 2010 Plan is further subject to detailed share-counting rules. As a result of such share-counting rules, full-value grants such as grants of restricted stock or RSUs count against shares remaining available for grant at a higher rate than grants of stock options and stock appreciation rights. For grants prior to March 1, 2019, each stock option or stock appreciation right grant is treated as using one available share for each share actually subject to such grant, whereas each restricted stock or RSU grant is treated as using three available shares for each share actually subject to such full-value grant. For grants on or after March 1, 2019, each stock option or stock appreciation right grant is treated as using one available share for each share actually subject to such grant, whereas each restricted stock or RSU grant is treated as using two and seven-tenths available shares for each share actually subject to such full-value grant. At December 31, 2019, there were approximately 24 million shares of common stock available for grant remaining under the Amended 2010 Plan.

Mattel recognized total share-based compensation expense related to stock options and RSUs (including Performance RSUs) of $56.0 million, $48.9 million, and $67.1 million during 2019, 2018, and 2017, respectively, which is included in other selling and administrative expenses in the consolidated statements of operations. As of December 31, 2019, total unrecognized compensation cost related to unvested share-based payments totaled $81.4 million and is expected to be recognized over a weighted-average period of 1.9 years.

Stock Options

Mattel recognized compensation expense of $11.3 million, $8.4 million, and $14.1 million for stock options during 2019, 2018, and 2017, respectively, which is included within other selling and administrative expenses in the consolidated statements of operations. There was no current year income tax benefit related to stock options during 2019, 2018 or 2017 as future tax benefits related to stock options were fully offset by a valuation allowance.

In 2018, Mattel granted market-based options under the Amended 2010 Plan to certain senior executives in connection with its April 26, 2018—April 26, 2021 and May 31, 2018—May 31, 2021 performance cycles. These performance options are earned at the initial target number of options granted based on achievement of a certain threshold of Mattel’s total shareholder return ("TSR") for the three-year performance cycle relative to the TSR realized by companies comprising the S&P 500 as of the first day of the performance cycle. If this threshold is not met at the end of the three-year cycle, no shares are earned. For the performance options granted during 2018 that remain outstanding at December 31, 2018, the range of possible outcomes is that between zero and 1.3 million shares could be earned. The fair value of these performance options has been estimated at the grant dates using a Monte Carlo valuation methodology, and the weighted-average grant-date fair value of performance options granted during 2018 was $4.21.

The fair values of all other options granted have been estimated using the Black-Scholes valuation model. The expected life of the options used in this calculation is the period of time the options are expected to be outstanding and has been determined based on historical exercise experience. Expected stock price volatility is based on the historical volatility of Mattel’s stock for a period approximating the expected life, the expected dividend yield is based on Mattel’s most recent actual annual dividend payout, and the risk-free interest rate is based on the implied yield available on U.S. Treasury zero-coupon issues approximating the expected life. The weighted-average grant-date fair value of options granted during 2019, 2018, and 2017 was $5.09, $5.46, and $3.37 respectively.

The following weighted-average assumptions were used in determining the fair value of options granted:



	2019		2018		2017
Expected life (in years)	5.5		5.1		5.0
Risk-free interest rate	1.7	%	2.8	%	1.8	%
Volatility factor	38.1	%	33.6	%	27.2	%
Dividend yield	—	%	—	%	4.0	%

The following is a summary of stock option information and weighted-average exercise prices for Mattel’s stock options:



	2019				2018				2017
	Shares		Weighted Average Exercise Price		Shares		Weighted Average Exercise Price		Shares		Weighted Average Exercise Price
	(In thousands, except weighted-average exercise price)
Outstanding at January 1	22,020		$	25.47	25,233		$	26.56	19,316		$	28.71
Granted	2,342		13.54		3,379		15.41		7,776		21.05
Exercised	—		—		—		—		(84	)	21.22
Forfeited	(266	)	17.64		(4,209	)	23.06		(832	)	25.84
Canceled	(1,586	)	26.79		(2,383	)	26.99		(943	)	26.31
Outstanding at December 31	22,510		$	24.22	22,020		$	25.47	25,233		$	26.56
Exercisable at December 31	16,576		$	27.32	16,051		$	28.10	14,038		$	29.08

The intrinsic value of a stock option is the amount by which the current market value of the underlying stock exceeds the exercise price of the option. There were no stock option exercises during 2019 and 2018. The total intrinsic value of options exercised during 2017 was $0.5 million. At December 31, 2019, options outstanding and options exercisable had no intrinsic value, with a weighted-average remaining life of 5.2 years and 4.0 years, respectively. Mattel uses treasury shares purchased under its share repurchase program to satisfy stock option exercises. Cash received from stock options exercised during 2017 was $1.8 million.

At December 31, 2019, stock options vested or expected to vest totaled 21.8 million shares, with an intrinsic value of $0.2 million, weighted-average exercise price of $24.52, and weighted-average remaining life of 5.1 years. During 2019, approximately 2 million stock options vested. The total grant-date fair value of stock options vested during 2019, 2018, and 2017 was approximately $8 million, $12 million, and $14 million, respectively.

Restricted Stock Units

RSUs are valued at the market value on the date of grant, adjusted by the present value of the expected dividends for RSUs that are not entitled to a dividend during the vest period. The expense for RSUs is evenly attributed to the periods in which the restrictions lapse, which is generally 3 years from the date of grant.

Compensation expense recognized related to grants of RSUs, excluding Performance RSUs, was $33.6 million, $37.5 million, and $55.2 million in 2019, 2018, and 2017, respectively, and was included within other selling and administrative expenses in the consolidated statements of operations. There was no current year income tax benefit related to RSUs during 2019, 2018, and 2017 as future tax benefits related to stock options were fully offset by a valuation allowance.

The following is a summary of RSU information and weighted-average grant-date fair values for Mattel’s RSUs, excluding Performance RSUs:



	2019				2018				2017
	Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value		Shares		Weighted Average Grant Date Fair Value
	(In thousands, except weighted-average grant-date fair value)
Unvested at January 1	4,721		$	17.22	4,898		$	21.95	3,243		$	28.85
Granted	1,687		13.28		3,345		15.71		4,205		19.39
Vested	(1,997	)	18.02		(2,048	)	21.02		(2,103	)	27.13
Forfeited	(547	)	16.48		(1,474	)	20.18		(447	)	23.57
Unvested at December 31	3,864		$	15.19	4,721		$	17.22	4,898		$	21.95

At December 31, 2019, RSUs expected to vest totaled 3.4 million shares, with a weighted-average grant-date fair value of $15.25. The total grant-date fair value of RSUs vested during 2019, 2018, and 2017 was $36.0 million, $43.2 million, and $57.0 million, respectively.

In addition to the expense and share amounts described above, Mattel recognized $11.0 million, $3.0 million, and $0.6 million during 2019, 2018, and 2017, respectively, for Performance RSUs granted in connection with its January 1, 2019—December 31, 2021, January 1, 2018—December 31, 2020, and January 1, 2017—December 31, 2019 LTIP performance cycles, more fully described in "Note 4 to the Consolidated Financial Statements—Employee Benefit Plans." During 2019, 2018, and 2017, there was no current year income tax benefit for Performance RSUs granted in connection with any of the performance cycles referenced above, as future tax benefits were fully offset by a valuation allowance.

Stockholders' Equity - Changes in Accumulated Balances for Each Component of Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Rollforward
Balance at beginning of period	$ 666,901	$ 1,257,197	$ 2,408,267
Other comprehensive income (loss) before reclassifications	3,072	(93,699)	78,781
Amounts reclassified from accumulated other comprehensive loss	(13,330)	16,259	82,462
Other Comprehensive (Loss) Income, Net of Tax	(10,258)	(77,440)	161,243
Balance at end of period	491,714	666,901	1,257,197
Derivative Instruments
AOCI Rollforward
Balance at beginning of period	11,411	(21,098)	17,469
Other comprehensive income (loss) before reclassifications	17,024	24,082	(55,377)
Amounts reclassified from accumulated other comprehensive loss	(17,394)	8,427	16,810
Other Comprehensive (Loss) Income, Net of Tax	(370)	32,509	(38,567)
Balance at end of period	11,041	11,411	(21,098)
Available-for-Sale Security
AOCI Rollforward
Balance at beginning of period	(6,547)	(2,799)	3,149
Other comprehensive income (loss) before reclassifications	(1,713)	(3,748)	(5,948)
Amounts reclassified from accumulated other comprehensive loss	0	0	0
Other Comprehensive (Loss) Income, Net of Tax	(1,713)	(3,748)	(5,948)
Balance at end of period	(8,260)	(6,547)	(2,799)
Employee Benefit Plans
AOCI Rollforward
Balance at beginning of period	(142,763)	(143,213)	(157,704)
Other comprehensive income (loss) before reclassifications	(31,158)	(7,382)	7,812
Amounts reclassified from accumulated other comprehensive loss	4,064	7,832	6,679
Other Comprehensive (Loss) Income, Net of Tax	(27,094)	450	14,491
Balance at end of period	(169,857)	(142,763)	(143,213)
Currency Translation Adjustments
AOCI Rollforward
Balance at beginning of period	(721,327)	(614,676)	(805,943)
Other comprehensive income (loss) before reclassifications	18,919	(106,651)	132,294
Amounts reclassified from accumulated other comprehensive loss	0	0	58,973
Other Comprehensive (Loss) Income, Net of Tax	18,919	(106,651)	191,267
Balance at end of period	(702,408)	(721,327)	(614,676)
AOCI Attributable to Parent
AOCI Rollforward
Balance at beginning of period	(859,226)	(781,786)	(943,029)
Other Comprehensive (Loss) Income, Net of Tax	(10,258)	(77,440)	161,243
Balance at end of period	$ (869,484)	$ (859,226)	$ (781,786)

Commitments and Contingencies - Additional Information (Detail)							1 Months Ended					12 Months Ended
	Apr. 26, 2015	Jan. 13, 2014 USD ($)	Dec. 23, 2013 USD ($)	Dec. 21, 2013 USD ($)	Jan. 24, 2013 USD ($)	Aug. 11, 2011 USD ($)	Aug. 31, 2011 USD ($)	Apr. 30, 2011 USD ($) LegalMatter	Jan. 31, 2010 USD ($)	Jun. 30, 2006 Case	Apr. 30, 1999 USD ($)	Dec. 31, 2019 USD ($) lawsuit class	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 11, 2014 USD ($)	Jul. 26, 2013 USD ($)	Dec. 31, 2012 USD ($)	Apr. 27, 2009 USD ($)	Jul. 17, 2008 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Royalty expense												$ 220,200,000	$ 224,000,000.0	$ 244,500,000
Liability for reported and incurred but not reported claims												12,000,000.0	$ 12,300,000
Workers Compensation Risks
Commitments and Contingencies Disclosure [Line Items]
Self-insured amount per occurrence												1,000,000.0
General And Automobile Liability Risks
Commitments and Contingencies Disclosure [Line Items]
Self-insured amount per occurrence												500,000
Product Liability Risks
Commitments and Contingencies Disclosure [Line Items]
Self-insured amount per occurrence												2,000,000.0
Property Risks
Commitments and Contingencies Disclosure [Line Items]
Self-insured amount per occurrence												1,000,000.0
MGA
Commitments and Contingencies Disclosure [Line Items]
Number of cases \| Case										3
Historical jury verdict																		$ 100,000,000	$ 100,000,000
Number of claimed trade secrets \| LegalMatter								26
Compensatory damages awarded by jury								$ 88,500,000
Number of other claimed trade secrets \| LegalMatter								88
Reduced compensatory damages awarded by court							$ 85,000,000.0
Punitive damages awarded							85,000,000.0
Attorney fees and costs awarded							140,000,000
Compensatory damages, punitive damages, and attorney fees and costs awarded by court							$ 310,000,000
Damages for alleged trade secret misappropriation appealed						$ 170,000,000
Attorney fees and costs appealed						$ 140,000,000
Amount of damages and attorney's fees and costs vacated by the appeals court					$ 172,500,000
Litigation accrual																	$ 138,000,000
Approximate amount of judgment finalized in the District Court, including interest				$ 138,000,000
Payment of judgment			$ 138,000,000
Accrued litigation liability												$ 0
MGA \| Minimum
Commitments and Contingencies Disclosure [Line Items]
Alleged trade secrets damages claimed more than		$ 1,000,000,000
Yellowstone
Commitments and Contingencies Disclosure [Line Items]
Alleged loss of profits											$ 1,000,000
Unpaid accounts receivable											4,000,000
Alleged business investments											3,000,000
Initial court appointed expert estimated loss of profits											$ 1,000,000
Court awarded damages from counterclaim									$ 4,000,000
Damages including attorney fees awarded by appeals court including inflation and interest																$ 17,000,000
Counterclaim awarded by Appeals Court															$ 7,500,000	$ 7,500,000
Damages awarded by Appeals Court including inflation and interest															$ 14,500,000
Loss contingency, additional fine on claim, percent	1.00%
Sleeper
Commitments and Contingencies Disclosure [Line Items]
Number of additional lawsuits pending \| lawsuit												28
Sleeper \| Minimum
Commitments and Contingencies Disclosure [Line Items]
Number of consumer classes \| class												15

Segment Information - Worldwide Revenues by Categories (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues	$ 1,473,705	$ 1,481,557	$ 860,063	$ 689,246	$ 1,524,281	$ 1,437,451	$ 844,706	$ 708,372	$ 4,504,571	$ 4,514,810	$ 4,881,493
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									5,064,574	5,075,529	5,514,125
Operating Segments \| Dolls
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									1,724,008	1,730,907	1,725,865
Operating Segments \| Infant, Toddler, and Preschool
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									1,257,646	1,417,820	1,677,223
Operating Segments \| Vehicles
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									1,101,338	1,065,452	1,242,790
Operating Segments \| Action Figures, Building Sets, and Games
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									981,582	861,350	868,247
Sales adjustments
Segment Reporting, Asset Reconciling Item [Line Items]
Revenues									$ (560,003)	$ (560,719)	$ (632,632)

Fair Value Measurements - Financial Assets and Liabilities Measured and Reported at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets:
Foreign currency forward exchange contracts	$ 15,002	$ 16,092
Available-for-sale	3,530	5,243
Total assets	18,532	21,335
Liabilities:
Foreign currency forward exchange contracts	2,976	2,910
Level 1
Assets:
Foreign currency forward exchange contracts	0	0
Available-for-sale	3,530	5,243
Total assets	3,530	5,243
Liabilities:
Foreign currency forward exchange contracts	0	0
Level 2
Assets:
Foreign currency forward exchange contracts	15,002	16,092
Available-for-sale	0	0
Total assets	15,002	16,092
Liabilities:
Foreign currency forward exchange contracts	2,976	2,910
Level 3
Assets:
Foreign currency forward exchange contracts	0	0
Available-for-sale	0	0
Total assets	0	0
Liabilities:
Foreign currency forward exchange contracts	$ 0	$ 0

Employee Benefit Plans - Narrative (Detail) $ in Thousands	3 Months Ended								12 Months Ended
Employee Benefit Plans - Narrative (Detail) $ in Thousands	Dec. 31, 2019 USD ($) incentive_program	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) incentive_program	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Employee Benefits Disclosure [Line Items]
Other selling and administrative expenses	$ (418,414)	$ (365,961)	$ (308,311)	$ (297,336)	$ (398,253)	$ (325,874)	$ (360,000)	$ (424,617)	$ (1,390,022)	$ (1,508,744)	$ (1,517,983)
Accumulated benefit obligation of defined benefit pension plans	608,400				549,700				608,400	549,700
Total estimated cash contributions to be made during the next fiscal year for defined benefit pension and postretirement benefit plans	$ 11,000								$ 11,000
Percentage of domestic defined benefit pension plan assets to total defined benefit pension plan assets	77.00%								77.00%
Percentage of total membership in pension plan insured											40.00%
Percentage limitation of an employee's total account balance that may be allocated to the Mattel Stock Fund in the Mattel, Inc. Personal Investment Plan	25.00%								25.00%
Liability for deferred compensation and excess benefit plans	$ 65,200				68,300				$ 65,200	68,300
Cash surrender value of life insurance policies	$ 75,700				$ 65,800				75,700	65,800
Expense for incentive compensation plans									$ 119,500	84,100	$ 19,400
Number of long-term incentive programs \| incentive_program	3								3
Long-term Incentive Program
Employee Benefits Disclosure [Line Items]
Long term incentive compensation expenses									$ 11,000	$ 3,000	$ 600
U.S. equity securities
Employee Benefits Disclosure [Line Items]
Target allocation for domestic defined benefit pension plan assets	42.00%								42.00%
Non US Equity Securities
Employee Benefits Disclosure [Line Items]
Target allocation for domestic defined benefit pension plan assets	28.00%								28.00%
Long-Term Bond Securities
Employee Benefits Disclosure [Line Items]
Target allocation for domestic defined benefit pension plan assets	20.00%								20.00%
US Treasury Securities
Employee Benefits Disclosure [Line Items]
Target allocation for domestic defined benefit pension plan assets	10.00%								10.00%
Defined benefit pension plans
Employee Benefits Disclosure [Line Items]
Estimated net actuarial loss (gain) and prior service credit that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in next fiscal year	$ 8,500								$ 8,500
Long-term rate of return on plan assets used to determine net periodic benefit cost for domestic defined benefit pension plans									6.00%	6.00%	6.30%
Postretirement benefit plans
Employee Benefits Disclosure [Line Items]
Estimated net actuarial loss (gain) and prior service credit that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in next fiscal year	$ (2,100)								$ (2,100)
Accounting Standards Update 2017-07
Employee Benefits Disclosure [Line Items]
Other selling and administrative expenses											$ 3,400

Leases - Cash Flow (Details) $ in Thousands	12 Months Ended
Leases - Cash Flow (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 105,015
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 38,795

Quarterly Financial Information (Unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information (Unaudited)



	First Quarter			Second Quarter			Third Quarter		Fourth Quarter
	(In thousands, except per share amounts)
Year Ended December 31, 2019
Net sales	$	689,246		$	860,063		$	1,481,557	$	1,473,705
Cost of sales	449,456			518,679			795,130		760,527
Gross profit	239,790			341,384			686,427		713,178
Advertising and promotion expenses	69,465			84,489			170,379		227,184
Other selling and administrative expenses	297,336			308,311			365,961		418,414
Operating (loss) income	(127,011		)	(51,416		)	150,087		67,580
(Loss) income before income taxes	(173,601		)	(95,824		)	101,955		9,182
Net (loss) income (a)	(176,296		)	(107,987		)	70,596		175
Net (loss) income (a) per common share - basic	$	(0.51	)	$	(0.31	)	$	0.20	$	0.00
Weighted average number of common shares	345,852			345,941			346,698		346,727
Net (loss) income per common share - diluted	$	(0.51	)	$	(0.31	)	$	0.20	$	0.00
Weighted average number of common and potential common shares	345,852			345,941			348,487		348,268



	First Quarter			Second Quarter			Third Quarter		Fourth Quarter
	(In thousands, except per share amounts)
Year Ended December 31, 2018
Net sales	$	708,372		$	844,706		$	1,437,451	$	1,524,281
Cost of sales	489,499			587,546			824,395		814,687
Gross profit	218,873			257,160			613,056		709,594
Advertising and promotion expenses	70,837			82,393			165,308		205,750
Other selling and administrative expenses	424,617			360,000			325,874		398,253
Operating (loss) income	(276,581		)	(185,233		)	121,874		105,591
(Loss) income before income taxes	(313,905		)	(230,064		)	72,592		54,274
Net (loss) income (a)	(311,253		)	(237,963		)	6,278		9,639
Net (loss) income (a) per common share - basic	$	(0.90	)	$	(0.69	)	$	0.02	$	0.03
Weighted average number of common shares	344,434			344,584			345,285		345,720
Net (loss) income (a) per common share - diluted	$	(0.90	)	$	(0.69	)	$	0.02	$	0.03
Weighted average number of common and potential common shares	344,434			344,584			345,672		345,846

Summary of Significant Accounting Policies - Property, Plant, and Equipment (Detail)	12 Months Ended
	Dec. 31, 2019
Buildings \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	10 years
Buildings \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	30 years
Machinery and equipment \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	3 years
Machinery and equipment \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	15 years
Software \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	3 years
Software \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	10 years
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	10 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	20 years
Tools, dies, and molds
Property, Plant and Equipment [Line Items]
Estimated useful lives, years	3 years

Stockholders' Equity - Classification and Amount of Reclassifications from Accumulated Other Comprehensive Income to Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for income taxes									$ (55,224)	$ (116,196)	$ (553,334)
Other non-operating expense, net									(2,650)	(7,331)	(68,110)
(Loss) income before income taxes	$ 9,182	$ 101,955	$ (95,824)	$ (173,601)	$ 54,274	$ 72,592	$ (230,064)	$ (313,905)	(158,288)	(417,103)	(501,245)
Net Loss	$ 175	$ 70,596	$ (107,987)	$ (176,296)	$ 9,639	$ 6,278	$ (237,963)	$ (311,253)	(213,512)	(533,299)	(1,054,579)
Derivative Instruments \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales									18,046
Provision for income taxes									(652)
Net Loss									17,394
Derivative Instruments \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of sales										(8,575)	(16,717)
Provision for income taxes										148	(93)
Net Loss										(8,427)	(16,810)
Employee Benefit Plans \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for income taxes									1,255	2,345	1,964
(Loss) income before income taxes									(5,319)	(10,177)	(8,643)
Net Loss									(4,064)	(7,832)	(6,679)
Amortization of prior service credit (cost) \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating expense, net									1,974	2,008	(29)
Recognized actuarial loss \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating expense, net									(7,201)	(8,198)	(8,511)
Curtailment loss \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating expense, net									(92)	(739)	(103)
Settlement loss \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Other non-operating expense, net									0	(3,248)	0
Currency Translation Adjustments \| Reclassification Out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision for income taxes									0	0	0
Other non-operating expense, net									0	0	(58,973)
Net Loss									$ 0	$ 0	$ (58,973)

Supplemental Financial Information

12 Months Ended

Dec. 31, 2019

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Supplemental Financial Information



	December 31, 2019		December 31, 2018
	(In thousands)
Inventories include the following:
Raw materials and work in process	$	103,123	$	115,966
Finished goods	392,381		426,923
	$	495,504	$	542,889
Other noncurrent assets include the following:
Identifiable intangibles (net of accumulated amortization of $248.0 million and $207.9 million at December 31, 2019 and 2018, respectively)	$	553,114	$	587,528
Deferred income taxes	67,900		49,937
Other	212,198		209,541
	$	833,212	$	847,006
Accrued liabilities include the following:
Incentive compensation	$	122,923	$	87,086
Royalties	94,228		98,011
Advertising and promotion	93,804		86,935
Lease liability	74,065		—
Other	384,493		422,239
	$	769,513	$	694,271
Other noncurrent liabilities include the following:
Benefit plan liabilities	212,280		186,380
Noncurrent tax liabilities	125,515		150,960
Other	101,206		132,329
	$	439,001	$	469,669



	For the Year Ended
	December 31, 2019			December 31, 2018			December 31, 2017
	(In thousands)
Currency transaction losses included in:
Operating income (loss)	$	164		$	(5,061	)	$	(29,678	)
Other non-operating expense, net	(527		)	(3,328		)	(6,525		)
Net transaction losses	$	(363	)	$	(8,389	)	$	(36,203	)
Other selling and administrative expenses include the following:
Design and development	$	197,226		$	205,368		$	225,245
Identifiable intangible asset amortization	$	40,112		$	39,095		$	23,273
Bad debt expense, net	$	967		$	40,894		$	17,568

Goodwill and Other Intangibles - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived intangible assets	$ 587,528,000	$ 553,114,000
Intangible assets, accumulated amortization	207,900,000	248,000,000.0
Indefinite-lived intangible assets	0	$ 0
Impairment of amortizable intangible assets	$ 4,300,000

Employee Benefit Plans - Assumptions Used to Calculate Net Periodic Benefit Cost for Domestic Defined Benefit Pension and Postretirement Benefit Plans (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pre-65
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate	7.00%	7.30%	7.00%
Ultimate cost trend rate	4.50%	4.50%		4.50%
Post-65
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate	6.80%	7.30%	7.80%
Ultimate cost trend rate	4.50%	4.50%		4.50%
Defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.10%	3.40%	3.90%
Long-term rate of return on plan assets	6.00%	6.00%	6.30%
Postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.10%	3.40%	3.90%
Annual increase in Medicare Part B premium	6.00%	6.00%	6.00%

Restructuring Charges - Cost and Expense Categories (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Structural Simplification Cost Savings Program
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	$ 21,516	$ 109,830
Structural Simplification Cost Savings Program \| Cost of sales
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	0	5,741
Structural Simplification Cost Savings Program \| Other selling and administrative
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	21,516	$ 104,089
Capital Light Initiative
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	37,571
Capital Light Initiative \| Cost of sales
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	18,579
Capital Light Initiative \| Other selling and administrative
Restructuring Cost and Reserve [Line Items]
Severance and other restructuring costs	$ 18,992

Employee Benefit Plans - Summary of Changes in Benefit Obligation and Plan Assets for Defined Benefit Pension and Postretirement Benefit Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in Plan Assets:
Plan assets at fair value, beginning of year	$ 401,929
Plan assets at fair value, end of year	431,747	$ 401,929
Net Amount Recognized in Consolidated Balance Sheets:
Noncurrent accrued benefit liability	(212,280)	(186,380)
Amounts Recognized in Accumulated Other Comprehensive Loss:
Tax benefits related to changes in benefit obligation and plan assets which are also included in accumulated other comprehensive loss	84,500	79,000
Defined benefit pension plans
Change in Benefit Obligation:
Benefit obligation, beginning of year	567,502	639,319
Service cost	4,479	4,223	$ 4,045
Interest cost	19,309	18,117	17,961
Impact of currency exchange rate changes	1,500	(7,793)
Actuarial loss (gain)	72,353	(34,214)
Benefits paid	(36,991)	(50,211)
Plan amendments	0	809
Settlements	0	(2,748)
Benefit obligation, end of year	628,152	567,502	639,319
Change in Plan Assets:
Plan assets at fair value, beginning of year	401,929	460,952
Actual return on plan assets	60,721	(18,162)
Employer contributions	3,670	18,216
Impact of currency exchange rate changes	2,418	(5,554)
Benefits paid	(36,991)	(50,211)
Settlements	0	(3,312)
Plan assets at fair value, end of year	431,747	401,929	460,952
Net Amount Recognized in Consolidated Balance Sheets:
Funded status, end of year	(196,405)	(165,573)
Current accrued benefit liability	(4,593)	(4,395)
Noncurrent accrued benefit liability	(191,812)	(161,178)
Net amount recognized	(196,405)	(165,573)
Amounts Recognized in Accumulated Other Comprehensive Loss:
Net actuarial loss (gain)	266,714	238,862
Prior service cost (credit)	182	220
Total amount recognized in accumulated other comprehensive loss, before tax	266,896	239,082
Postretirement benefit plans
Change in Benefit Obligation:
Benefit obligation, beginning of year	6,201	7,752
Service cost	1	1	2
Interest cost	201	208	812
Impact of currency exchange rate changes	0	0
Actuarial loss (gain)	1,486	(596)
Benefits paid	(2,108)	(1,164)
Plan amendments	0	0
Settlements	0	0
Benefit obligation, end of year	5,781	6,201	7,752
Change in Plan Assets:
Plan assets at fair value, beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	2,108	1,164
Impact of currency exchange rate changes	0	0
Benefits paid	(2,108)	(1,164)
Settlements	0	0
Plan assets at fair value, end of year	0	0	$ 0
Net Amount Recognized in Consolidated Balance Sheets:
Funded status, end of year	(5,781)	(6,201)
Current accrued benefit liability	(750)	(1,090)
Noncurrent accrued benefit liability	(5,031)	(5,111)
Net amount recognized	(5,781)	(6,201)
Amounts Recognized in Accumulated Other Comprehensive Loss:
Net actuarial loss (gain)	(1,201)	(3,071)
Prior service cost (credit)	(12,186)	(14,224)
Total amount recognized in accumulated other comprehensive loss, before tax	$ (13,387)	$ (17,295)