Income Taxes - Valuation Allowances Rollforward (Detail) (USD $) In Millions, unless otherwise specified					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Additions [Member]	Dec. 31, 2012 Additions [Member]	Dec. 31, 2011 Additions [Member]	Dec. 31, 2013 Reductions [Member]	Dec. 31, 2012 Reductions [Member]	Dec. 31, 2011 Reductions [Member]
Valuation Allowance [Abstract]
Balance at January 1	$ (818)	$ (922)	$ (555)	$ (454)
Valuation Allowance [Line Items]
Change in valuation allowances					(38)	(426)	(138)	142	59	37
Balance at December 31	$ (818)	$ (922)	$ (555)	$ (454)