Stockholder Rights Plan (Details Textual)	Sep. 30, 2013
Equity [Abstract]
Beneficial owner of common stock percentage	4.90%
Beneficial owner of common stock percentage in future	15.00%
Beneficial ownership percentage post standstill period for Berkshire Hathaway	50.00%
Period of review Shareholder Rights Plan	3 years

Minimum percentage ownership that if acquired will allow current stockholders other than the triggering beneficial stockholder the right to purchase common stock at half the market price.

No definition available.

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