Income Taxes Components of Provision for Income Taxes, Net (Details) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2016	[1]	Sep. 30, 2016	[1]	Jun. 30, 2016	[1]	Mar. 31, 2016	[1]	Dec. 31, 2015	[1]	Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current taxes:
U.S. Federal																	$ 1,136	$ 215	$ 214
U.S. State																	208	237	65
International																	327	417	204
Current taxes																	1,671	869	483
Deferred taxes:
U.S. Federal																	116	473	(125)
U.S. State																	(31)	(171)	(11)
International																	(331)	(221)	(180)
Deferred taxes																	(246)	81	(316)
Provision for income taxes, net	$ 414		$ 229		$ 307		$ 475		$ 453		$ 161		$ 266		$ 71		$ 1,425	$ 950	$ 167

[1] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted-average shares outstanding for each period.