Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net actuarial gains (losses) of defined benefit plans:
Adjustment, net of tax benefit (expense)	$ 36	$ 25	$ (60)
Recognized within Net income, net of tax benefit (expense)	(25)	(21)	(37)
Prior service (cost) credit of defined benefit plans:
Adjustment, net of tax benefit (expense)	(11)	0	1
Recognized within Net income, net of tax benefit (expense)	0	0	2
Derivative instruments:
Recognized within Net income, net of tax benefit (expense)	$ (1)	$ (1)	$ (1)