Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2021	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income tax expense, elimination of disproportionate tax	$ 11	$ 5

Income Tax Expense, Elimination of Disproportionate Tax Effect from Accumulated Other Comprehensive Loss, Amount

No definition available.

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Namespace Prefix:	mas_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration