Organization, Consolidation and Presentation of Financial Statements (Details)	Sep. 30, 2014	Feb. 27, 2014
USG Boral Building Products
Schedule of Equity Method Investments [Line Items]
Ownership Percentage - Other equity method investment	50.00%	50.00%
Boral Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage by joint venture partner of equity method investment		50.00%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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