Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Mattel's provision for income taxes was $20.3 million and $11.9 million for the three months ended March 31, 2021 and 2020, respectively. During the three months ended March 31, 2021, Mattel recognized a net discrete tax expense of $7.3 million, primarily related to income taxes recorded on a discrete basis in various jurisdictions and an expense for reassessments of prior year's tax liabilities. During the three months ended March 31, 2020, Mattel recognized a net discrete tax expense of $6.4 million primarily related to an expense for reassessments of prior years' tax liabilities and income taxes recorded on a discrete basis in various jurisdictions. As a result of the establishment of a valuation allowance on U.S. deferred tax assets in 2017, there was no U.S. tax benefit provided for U.S. losses during the three months ended March 31, 2021 and 2020. Evaluating the need for and the amount of a valuation allowance for deferred tax assets often requires significant judgment and extensive analysis of all available evidence to determine whether it is more-likely-than-not that these assets will be realized. Mattel maintains a valuation allowance on its deferred tax assets until there is sufficient evidence to support the release of all or some portion of these allowances. Release of the valuation allowance would result in the recognition of a portion of these deferred tax assets and a decrease to income tax expense for the period the release is recorded. However, the exact timing and amount, if any, of the valuation allowance release are subject to change depending on the level of earnings that Mattel is able to achieve in the tax jurisdictions in which a valuation allowance has been recorded. In the normal course of business, Mattel is regularly audited by federal, state, and foreign tax authorities. Based on the current status of federal, state, and foreign audits, Mattel believes it is reasonably possible that in the next twelve months, the total unrecognized tax benefits could decrease by approximately $31.6 million related to the settlement of tax audits and/or the expiration of statutes of limitations. The ultimate settlement of any particular issue with the applicable taxing authority could have a material impact on Mattel's consolidated financial statements.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.