Investment Securities - Schedule Of Amortized Cost And Fair Value By Contractual Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Held-to-Maturity, 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	712
Total	712
Held-to-Maturity, 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	705
Fair Value	705	$ 10
Available-for-Sale, Amortized Cost
Within 1 year	17
After 1 year through 5 years	149
After 5 years through 10 years	351
After 10 years	879
Subtotal	1,396
Government agency issued MBS and CMO	7,358
Securities available for sale, amortized cost	8,754
Available-for-Sale, Fair Value
Within 1 year	18
After 1 year through 5 years	149
After 5 years through 10 years	349
After 10 years	879
Subtotal	1,395
Government agency issued MBS and CMO	7,312
Securities available-for-sale	$ 8,707	$ 8,047