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Fair Value of Financial Investments and Liabilities - Non-Recurring Fair Value Measurements (Detail) (Non-Recurring Investments [Member], USD $) In Millions, unless otherwise specified | Dec. 31, 2012
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | $ 2
Private Equity Funds [Member] |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | 2
Assets at Fair Value (Level 3) [Member] |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | 2
Assets at Fair Value (Level 3) [Member] | Private Equity Funds [Member] |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | 2
Gains (Losses) [Member] |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | (2)
Gains (Losses) [Member] | Private Equity Funds [Member] |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Fair value on a non-recurring basis of financial investments | $ (2)

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- Definition Fair Value Measured on nonrecurring basis investments. + References No definition available. + Details
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Namespace Prefix: | mas_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration