Investment Securities - Schedule Of Amortized Cost And Fair Value By Contractual Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
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	701
Total	701
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	650
Fair Value	650	$ 705
Amortized Cost
Within 1 year	52
After 1 year through 5 years	118
After 5 years through 10 years	349
After 10 years	1,059
Subtotal	1,578
Government agency issued MBS and CMO	8,245
Securities available for sale, amortized cost	9,823
Fair Value
Within 1 year	52
After 1 year through 5 years	115
After 5 years through 10 years	328
After 10 years	986
Subtotal	1,481
Government agency issued MBS and CMO	7,761
Securities available-for-sale	$ 9,242	$ 8,707