Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Accumulated other comprehensive income (loss)
Beginning balance	$ 2,733	$ 2,358	$ 2,718	$ 2,201
Other comprehensive loss, net of tax	(97)	(9)	(134)	(2)
Ending balance	2,693	2,498	2,693	2,498
Investment Securities
Accumulated other comprehensive income (loss)
Beginning balance	(43)	37	15	52
Unrealized (loss) gain	(82)	(2)	(159)	(22)
Less: Tax (benefit) provision	(14)	0	(33)	(5)
Net unrealized (loss) gain	(68)	(2)	(126)	(17)
Other comprehensive loss, net of tax	(68)	(2)	(126)	(17)
Ending balance	(111)	35	(111)	35
Cash Flow Hedges
Accumulated other comprehensive income (loss)
Beginning balance	41	17	20	(5)
Unrealized (loss) gain	(24)	(9)	5	17
Less: Tax (benefit) provision	(6)	(1)	2	4
Net unrealized (loss) gain	(18)	(8)	3	13
Reclassifications (into) out of AOCI	(14)	1	(14)	2
Less: Tax (benefit) provision	(3)	0	(3)	0
Other comprehensive loss, net of tax	(29)	(7)	(8)	15
Ending balance	$ 12	$ 10	$ 12	$ 10