Litigation (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2011
Litigation (Textuals)
Approximate number of homes where the presence of Knauf Tianjin wallboard has been confirmed	262
Approximate number of property damage claims resolved	138
Accrual for estimated costs of resolving the Chinese wallboard property damage claims	$ 15
Receivables Related to Settlement	$ 10
Maximum [Member]
Litigation (Textuals)
Range of average-size houses that the amount of Knauf Tianjin wallboard potentially sold by L&W Supply Corporation could completely furnish	300
Minimum [Member]
Litigation (Textuals)
Range of average-size houses that the amount of Knauf Tianjin wallboard potentially sold by L&W Supply Corporation could completely furnish	250

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14435-108349

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14557-108349

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant