Income Taxes (Income (Loss) From Operations Before Provision (Benefit) For Income Tax) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income (Loss) From Operations Before Provision (Benefit) For Income Taxes [Line Items]
Income (loss) from operations before provision (benefit) for income taxes	$ 1,598	$ (2,239)	$ (95)
Domestic [Member]
Income (Loss) From Operations Before Provision (Benefit) For Income Taxes [Line Items]
Income (loss) from operations before provision (benefit) for income taxes	1,486	(2,231)	(146)
Foreign [Member]
Income (Loss) From Operations Before Provision (Benefit) For Income Taxes [Line Items]
Income (loss) from operations before provision (benefit) for income taxes	$ 112	$ (8)	$ 51