Investment Securities - Schedule Of Amortized Cost And Fair Value By Contractual Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Amortized Cost
Within 1 year	$ 0
After 1 year through 5 years	0
After 5 years through 10 years	0
After 10 years	0
Subtotal	0
Government agency issued MBS and CMO	1,362
Total	1,362
Fair Value
Within 1 year	0
After 1 year through 5 years	0
After 5 years through 10 years	0
After 10 years	0
Subtotal	0
Government agency issued MBS and CMO	1,214
Fair Value	1,214	$ 1,209
Amortized Cost
Within 1 year	9
After 1 year through 5 years	127
After 5 years through 10 years	391
After 10 years	1,497
Subtotal	2,024
Government agency issued MBS and CMO	8,066
Securities available for sale, amortized cost	10,090
Fair Value
Within 1 year	9
After 1 year through 5 years	123
After 5 years through 10 years	357
After 10 years	1,355
Subtotal	1,844
Government agency issued MBS and CMO	7,110
Securities available-for-sale	$ 8,954	$ 8,836