Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current income tax expense:
U.S. federal	$ 2,107	$ 2,136	$ 1,730
U.S. state and local	335	264	288
Non-U.S.	416	412	514
Total current income tax expense	2,858	2,812	2,532
Deferred income tax expense (benefit):
U.S. federal	(23)	352	113
U.S. state and local	(5)	39	4
Non-U.S.	(55)	(97)	(120)
Total deferred income tax expense	(83)	294	(3)
Income tax provision (benefit)	$ 2,775	$ 3,106	$ 2,529