Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount of premium associated with contractual redemption of certain notes upon occurrence of specified event or events.

+ References

No definition available.

+ Details

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Namespace Prefix:	usg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent of redemption price equal to principal amount.

+ References

No definition available.

+ Details

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Namespace Prefix:	usg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

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Debt - Senior Notes (Details) - USD ($) $ in Millions	12 Months Ended
Debt - Senior Notes (Details) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,089		$ 1,089
5.5% senior notes due 2025
Debt Instrument [Line Items]
Stated interest rate	5.50%			5.50%
Long-term debt, gross	$ 350		350
Percentage of purchase price of notes at their principal amount	101.00%
Percentage of principal amount of the notes being redeemed	100.00%
4.875% senior notes due 2027
Debt Instrument [Line Items]
Stated interest rate	4.875%	4.875%
Long-term debt, gross	$ 500		$ 0
Percentage of purchase price of notes at their principal amount	101.00%
Percentage of principal amount of the notes being redeemed	100.00%