CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 395	$ 594
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	5	29
Net unrealized gains (losses) on securities	322	(262)
Net unrealized gains (losses) on derivatives	(1)	0
Total other comprehensive income (loss), net of tax	326	(233)
Total comprehensive income	$ 721	$ 361