Investment Securities - Schedule Of Investments Within The Available For Sale Portfolio That Had Unrealized Losses (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Unrealized Losses
Fair value, less than 12 months	$ 4,936	$ 1,400
Unrealized losses, less than 12 months	(90)	(6)
Fair value, 12 months or longer	522	0
Unrealized loss, 12 months or longer	(22)	0
Fair value, total	5,458	1,400
Unrealized losses, total	(112)	(6)
U.S. treasuries
Unrealized Losses
Fair value, less than 12 months		307
Unrealized losses, less than 12 months		0
Fair value, 12 months or longer		0
Unrealized loss, 12 months or longer		0
Fair value, total		307
Unrealized losses, total		0
Government agency issued MBS
Unrealized Losses
Fair value, less than 12 months	2,973	426
Unrealized losses, less than 12 months	(41)	(2)
Fair value, 12 months or longer	184	0
Unrealized loss, 12 months or longer	(8)	0
Fair value, total	3,157	426
Unrealized losses, total	(49)	(2)
Government agency issued CMO
Unrealized Losses
Fair value, less than 12 months	1,436	586
Unrealized losses, less than 12 months	(37)	(3)
Fair value, 12 months or longer	248	0
Unrealized loss, 12 months or longer	(10)	0
Fair value, total	1,684	586
Unrealized losses, total	(47)	(3)
Other U.S. government agencies
Unrealized Losses
Fair value, less than 12 months	459	80
Unrealized losses, less than 12 months	(11)	(1)
Fair value, 12 months or longer	90	0
Unrealized loss, 12 months or longer	(4)	0
Fair value, total	549	80
Unrealized losses, total	(15)	(1)
States and municipalities
Unrealized Losses
Fair value, less than 12 months	68	1
Unrealized losses, less than 12 months	(1)	0
Fair value, 12 months or longer	0	0
Unrealized loss, 12 months or longer	0	0
Fair value, total	68	1
Unrealized losses, total	$ (1)	$ 0