Consolidated Statements of Comprehensive Income Parenthetical (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Tax on foreign currency translation	$ (46)	$ 0	$ 0
Tax on reclassification adjustment for amounts recognized in income	0	0	0
Defined benefit plans:
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	36	10	9
Tax on decrease (increase) in net actuarial losses	(135)	34	(54)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	13	1	1
Tax on prior service cost from plan amendments	0	0	3
Tax on deferred derivative gains (losses)	1	1	0
Tax on reclassification adjustment for amounts recognized in income	(1)	0	(3)
Tax on unrealized investment gains	$ 1	$ 0	$ 0