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Earnings (Loss) Per Share (Details Textual) (USD $)
In Millions, unless otherwise specified
 12 Months Ended 1 Months Ended
Dec. 31, 2014
Apr. 30, 2014
Dec. 31, 2013
Earnings (Loss) Per Share [Line Items]      
Debt conversion, aggregate principal amount $ 75us-gaap_DebtConversionOriginalDebtAmount1    
10% convertible senior notes due 2018      
Earnings (Loss) Per Share [Line Items]      
Debt conversion, aggregate principal amount   $ 75us-gaap_DebtConversionOriginalDebtAmount1
/ us-gaap_DebtInstrumentAxis
= usg_TenPercentConvertibleSeniorNotesDueTwoThousandEighteenMember		 $ 325us-gaap_DebtConversionOriginalDebtAmount1
/ us-gaap_DebtInstrumentAxis
= usg_TenPercentConvertibleSeniorNotesDueTwoThousandEighteenMember
Stated interest rate 10.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= usg_TenPercentConvertibleSeniorNotesDueTwoThousandEighteenMember		   10.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= usg_TenPercentConvertibleSeniorNotesDueTwoThousandEighteenMember