Other Income/(Loss) (Details) - Operating Segments [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Non-Financial Services
Net periodic pension and OPEB income/(cost), excluding service cost	$ 365	$ 344	$ 1,144	$ 1,005
Investment-related interest income	91	50	247	163
Interest income/(expense) on income taxes	(1)	9	1	8
Realized and unrealized gains/(losses) on cash equivalents and marketable securities	(14)	(13)	11	52
Gains/(Losses) on changes in investments in affiliates	(4)	(1)	(6)	180
Royalty income	171	174	475	494
Other	101	109	207	224
Total	709	672	2,079	2,126
Financial Services
Investment-related interest income	33	18	78	57
Interest income/(expense) on income taxes	(1)	(2)	(2)	11
Insurance premiums earned	0	38		118
Other	13	78	65	119
Total	$ 45	$ 132	$ 141	$ 305