Disposition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 02, 2014
Disposition
(Gain) loss on disposition of operations	$ (3)	$ 74	$ 688
LBL
Disposition
Disposal Group, Including Discontinued Operation, Consideration				$ 797
Cash and retention tax benefits				$ 596
(Gain) loss on disposition of operations		101	698
Loss on disposition, after-tax		60	$ 521
Reduction in goodwill, included in loss on disposition, pre-tax		$ 22