Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 41	$ 47	$ 68	$ 86
Other comprehensive income (loss), net of tax
Investment securities	2	1	2	16
Derivatives and hedging activities	(5)	(9)	(4)	(37)
Other comprehensive loss, net of tax	(3)	(8)	(2)	(21)
Comprehensive income	$ 38	$ 39	$ 66	$ 65