CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 503	$ 215	$ 1,299	$ 914
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	16	(16)	46	(55)
Net unrealized gains (losses) on securities	(4)	(28)	60	382
Net unrealized gains (losses) on derivatives	1	1	2	3
Defined benefit plans	0	0	5	6
Other	0	0	(1)	0
Total other comprehensive income (loss), net of tax	13	(43)	112	336
Total comprehensive income	$ 516	$ 172	$ 1,411	$ 1,250