Share Based Compensation (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	6 Months Ended
Jun. 30, 2012 Installments
Stock Options [Member]
Share Based Compensation (Textual) [Abstract]
Stock option granted	760,687
Vesting period	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Vesting Installments	4
Share-based compensation arrangement by share-based payment award fair value assumptions expected volatility calculation	50% weighting of our historical volatilities and 50% weighting of our implied volatilities
Share based compensation arrangement by share based payment award fair value assumptions historical expected volatility	50.00%
Share based compensation arrangement by share based payment award fair value assumptions implied expected volatility	50.00%
Expected volatility	59.03%
Risk-free rate	1.24%
Expected term (in years)	6 years 3 months 4 days
Expected dividends	$ 0
Fair value of stock option granted	$ 8.39
Expiration period for stock options	10 years
Restricted Stock Units [Member]
Share Based Compensation (Textual) [Abstract]
Vesting period	1 year
Share-based Compensation Arrangement by Share-based Payment Award, Vesting Installments	4
Shares granted	535,121
Average fair value of shares granted	$ 15.03
Performance Shares [Member]
Share Based Compensation (Textual) [Abstract]
Vesting period	3 years
Expected volatility	67.63%
Risk-free rate	0.36%
Expected term (in years)	2 years 10 months 21 days
Expected dividends	$ 0
Shares granted	225,127
Average fair value of shares granted	$ 22.96
Performance Shares [Member] \| Maximum [Member]
Share Based Compensation (Textual) [Abstract]
Range for number of performance shares earned Maximum	200.00%
Performance Shares [Member] \| Minimum [Member]
Share Based Compensation (Textual) [Abstract]
Range for number of performance shares earned Minimum	0.00%

Share based compensation arrangement by share based payment award award expiration period.

No definition available.

Name:	usg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriod
Namespace Prefix:	usg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award fair value assumptions expected volatility calculation.

+ References

No definition available.

+ Details

Name:	usg_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityCalculations
Namespace Prefix:	usg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award fair value assumptions historical expected volatility.

+ References

No definition available.

+ Details

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

- Definition

Share based compensation arrangement by share based payment award fair value assumptions implied expected volatility.

+ References

No definition available.

+ Details

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

- Definition

Share-based compensation arrangement by share-based payment award terms of award maximum.

+ References

No definition available.

+ Details

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

- Definition

Share-based compensation arrangement by share-based payment award terms of award minimum.

+ References

No definition available.

+ Details

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

- Definition

Share-based compensation arrangement by share-based payment award, vesting installments.

+ References

No definition available.

+ Details

Name:	usg_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingInstallments
Namespace Prefix:	usg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	usg_ShareBasedCompensationTextualAbstract
Namespace Prefix:	usg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated amount of dividends to be paid to holders of the underlying shares (expected dividends) over the option's term. Dividends are taken into account because payment of dividends to shareholders reduces the fair value of the underlying shares, and option holders generally do not receive dividends.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendPayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.D.2)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section D

-Subsection 2

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration