New Accounting Pronouncements	9 Months Ended
Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and most industry specific guidance. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new guidance establishes a five-step model to achieve that core principle and also requires additional disclosures about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts. Mattel adopted ASU 2014-09 and its related amendments on January 1, 2018 using the modified retrospective transition method. For additional information, see "Note 15 to the Consolidated Financial Statements — Revenues." In October 2016, the FASB issued ASU 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory, which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 became effective for interim and annual reporting periods beginning on January 1, 2018. For additional information, see "Note 21 to the Consolidated Financial Statements - Income Taxes." In March 2017, the FASB issued ASU 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires entities that sponsor defined benefit plans to (i) present service cost within operations, if such a subtotal is presented, (ii) other components of net benefit costs should be presented separately outside of income from operations, if such a subtotal is presented, and (iii) only the service cost component should be capitalized, when applicable. If a separate line item is not used, the line item in the income statement where the other components of net benefit costs are included must be disclosed. Further, gains and losses from curtailments and settlements, and the cost of certain termination benefits should be reported in the same manner as other components of net benefit cost. ASU 2017-07 became effective for interim and annual reporting periods beginning on January 1, 2018. The retrospective adoption of ASU 2017-07 in the first quarter of 2018 did not have a material effect on Mattel’s consolidated financial statements, as discussed in "Note 16 to the Consolidated Financial Statements—Employee Benefit Plans." Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases, and subsequent amendments to the initial guidance: ASU 2017-13, ASU 2018-10, and ASU 2018-11 (collectively the “new lease standards”). The new lease standards require a lessee to recognize a lease asset and lease liability on its balance sheet for all leases with a term greater than 12 months. In July 2018, the FASB issued ASU 2018-11, which provides entities with an additional transition method to adopt the new lease standards at the adoption date, versus the beginning of the earliest period presented, and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The new lease standards will be effective for interim and annual reporting periods beginning on January 1, 2019. Mattel is currently evaluating the impact of the adoption of the new lease standards on its operating results and financial position, which based on a preliminary assessment, is expected to have a material impact on its financial position. 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. ASU 2017-12 will be effective for interim and annual reporting periods beginning on January 1, 2019. Early application is permitted in any interim period after issuance of the update. Mattel is currently evaluating the impact of the adoption of ASU 2017-12 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 caused by the Tax Act to retained earnings. ASU 2018-02 will become effective for interim and annual reporting periods beginning on January 1, 2019. Early adoption of the amendments is permitted, including adoption in any interim period, for reporting periods for which financial statements have not yet been issued. Mattel is currently evaluating the impact of the adoption of ASU 2018-02 on its consolidated financial statements. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation: Improvements to Nonemployee Share-Based Payment Accounting, which expands the scope of current stock compensation recognition standards to include share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 will become effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity's adoption date of ASU 2014-09, which Mattel adopted on January 1, 2018. Mattel is currently evaluating the impact of the adoption of ASU 2018-07 on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement: 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 fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. 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 is currently evaluating the impact of the adoption of ASU 2018-13 on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General: 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 fiscal years ending after December 15, 2020. 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 August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software: Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract, which aligns the requirement for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. ASU 2018-15 will become effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption of the amendments is permitted, including adoption in any interim period. The amendments should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Mattel is currently evaluating the impact of the adoption of ASU 2018-15 on its consolidated financial statements.

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition, and most industry specific guidance. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new guidance establishes a five-step model to achieve that core principle and also requires additional disclosures about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts. Mattel adopted ASU 2014-09 and its related amendments on January 1, 2018 using the modified retrospective transition method. For additional information, see "Note 15 to the Consolidated Financial Statements — Revenues."

In October 2016, the FASB issued ASU 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory, which requires an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-16 became effective for interim and annual reporting periods beginning on January 1, 2018. For additional information, see "Note 21 to the Consolidated Financial Statements - Income Taxes."

In March 2017, the FASB issued ASU 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires entities that sponsor defined benefit plans to (i) present service cost within operations, if such a subtotal is presented, (ii) other components of net benefit costs should be presented separately outside of income from operations, if such a subtotal is presented, and (iii) only the service cost component should be capitalized, when applicable. If a separate line item is not used, the line item in the income statement where the other components of net benefit costs are included must be disclosed. Further, gains and losses from curtailments and settlements, and the cost of certain termination benefits should be reported in the same manner as other components of net benefit cost. ASU 2017-07 became effective for interim and annual reporting periods beginning on January 1, 2018. The retrospective adoption of ASU 2017-07 in the first quarter of 2018 did not have a material effect on Mattel’s consolidated financial statements, as discussed in "Note 16 to the Consolidated Financial Statements—Employee Benefit Plans."

Accounting Pronouncements Not Yet Adopted

In February 2016, the FASB issued ASU 2016-02, Leases, and subsequent amendments to the initial guidance: ASU 2017-13, ASU 2018-10, and ASU 2018-11 (collectively the “new lease standards”). The new lease standards require a lessee to recognize a lease asset and lease liability on its balance sheet for all leases with a term greater than 12 months. In July 2018, the FASB issued ASU 2018-11, which provides entities with an additional transition method to adopt the new lease standards at the adoption date, versus the beginning of the earliest period presented, and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The new lease standards will be effective for interim and annual reporting periods beginning on January 1, 2019. Mattel is currently evaluating the impact of the adoption of the new lease standards on its operating results and financial position, which based on a preliminary assessment, is expected to have a material impact on its financial position.

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. ASU 2017-12 will be effective for interim and annual reporting periods beginning on January 1, 2019. Early application is permitted in any interim period after issuance of the update. Mattel is currently evaluating the impact of the adoption of ASU 2017-12 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 caused by the Tax Act to retained earnings. ASU 2018-02 will become effective for interim and annual reporting periods beginning on January 1, 2019. Early adoption of the amendments is permitted, including adoption in any interim period, for reporting periods for which financial statements have not yet been issued. Mattel is currently evaluating the impact of the adoption of ASU 2018-02 on its consolidated financial statements.

In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation: Improvements to Nonemployee Share-Based Payment Accounting, which expands the scope of current stock compensation recognition standards to include share-based payment transactions for acquiring goods and services from nonemployees. ASU 2018-07 will become effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity's adoption date of ASU 2014-09, which Mattel adopted on January 1, 2018. Mattel is currently evaluating the impact of the adoption of ASU 2018-07 on its consolidated financial statements.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement: 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 fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. 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 is currently evaluating the impact of the adoption of ASU 2018-13 on its consolidated financial statements.

In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General: 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 fiscal years ending after December 15, 2020. 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 August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software: Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract, which aligns the requirement for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. ASU 2018-15 will become effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption of the amendments is permitted, including adoption in any interim period. The amendments should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Mattel is currently evaluating the impact of the adoption of ASU 2018-15 on its consolidated financial statements.