Primary Components of Net Deferred Tax Asset (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Deferred Income Tax Assets and Liabilities [Line Items]
Accrued related party interest	$ 17	$ 15
Net operating loss and capital loss carryovers	102	99
Alternative minimum tax credits	4	4
Property and equipment	(19)	(18)
Investments in domestic and foreign affiliates	(4)	(3)
Derivatives	2	1
Deferred revenue and other	51	50
Subtotal	153	148
Less: Valuation allowance	(63)	(47)
Net deferred tax asset	$ 90	$ 101