Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 964	$ 783
Change in net unrealized gain (loss) on available for sale securities:
Net unrealized gain (loss)	227	(108)
Other reclassifications included in other revenue	(1)	0
Amortization of amounts previously recorded upon transfer to held to maturity from available for sale	12	9
Other comprehensive income (loss), before tax	238	(99)
Income tax effect	(57)	24
Other comprehensive income (loss), net of tax	181	(75)
Comprehensive Income	$ 1,145	$ 708