Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total Other comprehensive income (loss), net of tax	$ 16	$ (318)	$ 118	$ (587)
Cumulative translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Pretax	(10)	(352)	76	(628)
Total Other comprehensive income (loss), net of tax	(2)	(341)	86	(626)
Retirement plans and other retiree benefits adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, Pretax	9	14	9	13
Reclassification from AOCI, Pretax	15	22	47	66
Other comprehensive income (loss), Pretax	24	36	56	79
Other comprehensive income (loss), before reclassifications, Net of Tax	7	9	7	8
Reclassification from AOCI, Net of Tax	9	16	32	44
Total Other comprehensive income (loss), net of tax	16	25	39	52
Available-for-sale securities:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, Pretax	0	(7)	0	(27)
Reclassification from AOCI, Pretax	(1)	7	(1)	14
Other comprehensive income (loss), Pretax	(1)	0	(1)	(13)
Other comprehensive income (loss), before reclassifications, Net of Tax	0	(5)	0	(18)
Reclassification from AOCI, Net of Tax	(1)	5	(1)	10
Total Other comprehensive income (loss), net of tax	(1)	0	(1)	(8)
Cash flow hedges:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before reclassifications, Pretax	1	16	(6)	17
Reclassification from AOCI, Pretax	1	(5)	1	(12)
Other comprehensive income (loss), Pretax	2	11	(5)	5
Other comprehensive income (loss), before reclassifications, Net of Tax	0	11	(4)	12
Reclassification from AOCI, Net of Tax	1	(4)	1	(8)
Total Other comprehensive income (loss), net of tax	1	7	(3)	4
Total Other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), Pretax	15	(305)	126	(557)
Total Other comprehensive income (loss), net of tax	$ 14	$ (309)	$ 121	$ (578)