CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 462	$ 393	$ 1,056	$ 796
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	(44)	23	(15)	30
Net unrealized gains (losses) on securities	(130)	57	(392)	64
Net unrealized gains (losses) on derivatives	0	0	0	1
Defined benefit plans	0	0	0	5
Other	0	0	0	(1)
Total other comprehensive income (loss), net of tax	(174)	80	(407)	99
Total comprehensive income	$ 288	$ 473	$ 649	$ 895