Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other Comprehensive Income (Loss):
Tax on foreign currency translation	$ 0	$ 0	$ 0	$ 0
Tax on reclassification adjustment for amounts recognized in income	0	0	0	0
Defined benefit plans:
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	3	2	7	4
Tax on decrease in net actuarial losses	2	7	2	7
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements and divestitures	0	0	0	0
Tax on prior service cost from plan amendments	0	(2)	0	(2)
Tax on deferred derivative gains	1	0	1	0
Tax on reclassification adjustment for amounts recognized in income	1	(2)	1	(2)
Tax on unrealized investment gains (losses)	$ 0	$ 0	$ 0	$ 0