CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 2,098	$ 1,480	$ 1,313
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	(31)	(8)	(76)
Net unrealized [gains (losses)] on securities:
Net unrealized gains (losses) on securities	(465)	7	47
Net unrealized gains on derivatives:
Net unrealized gains (losses) on derivatives	0	3	4
Defined benefit plans:
Defined benefit plans	(23)	28	(34)
Other	0	(1)	0
Total other comprehensive income (loss), net of tax	(519)	29	(59)
Total comprehensive income	$ 1,579	$ 1,509	$ 1,254