Consolidated Statements of Total Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Comprehensive Income [Abstract]
Shareholders' comprehensive income (loss)	$ 1,627	$ 1,739	$ 1,087
Net income attributable to redeemable noncontrolling interest	2	1	0
Net income attributable to other noncontrolling interest	0	0	1
Other comprehensive income (loss) attributable to redeemable noncontrolling interest	(19)	2	0
Total comprehensive income	$ 1,610	$ 1,742	$ 1,088