Discontinued Operations - Other Financial Information (Details) - Spinoff - TopBuild - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Selected financial information of discontinued operations
Depreciation and amortization	$ 0	$ 3
Capital expenditures	$ 0	$ 2

Amount of depreciation and amortization expense attributable to disposal group, including, but not limited to, discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

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