Adjustments to Preliminary Purchase Price Allocation (Detail) (Oakleaf [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Jul. 28, 2011
Business Acquisition [Line Items]
Accounts and other receivables	$ 71	$ 70
Other current assets	28	28
Property and equipment	70	72
Goodwill	328	327
Other intangible assets	87	87
Accounts payable	(82)	(82)
Accrued liabilities	(48)	(48)
Deferred income taxes, net	(9)	(10)
Other liabilities	(13)	(12)
Total purchase price	432	432	432
Adjustments [Member]
Business Acquisition [Line Items]
Accounts and other receivables	1
Other current assets
Property and equipment	(2)
Goodwill	1
Other intangible assets
Accounts payable
Accrued liabilities
Deferred income taxes, net	1
Other liabilities	(1)
Total purchase price