Securities - Summary of Held-to-Maturity and Available-for-Sale Securities Having Continuous Unrealized Loss Position (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	$ 3,096	$ 1,846
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	205	44
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	2,136	1,683
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	403	72
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	5,232	3,529
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	608	116
Debt Securities | U.S. Treasury Obligations
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	197	45
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	1
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	197	45
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	1
Debt Securities | U.S. Government and GSE obligations
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	421	317
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	44	7
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	959	185
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	204	8
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	1,380	502
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	248	15
Debt Securities | GSE Certificates
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	683	846
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	58	28
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	252	293
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	54	17
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	935	1,139
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	112	45
Debt Securities | GSE CMOs
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	800	491
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	73	8
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	596	926
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	122	37
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	1,396	1,417
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	195	45
Debt Securities | Asset-backed Securities
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	227	130
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	7	1
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	180	135
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	8	2
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	407	265
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	15	3
Debt Securities | Municipal Bonds
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	7	8
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	1
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	7	8
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	1
Debt Securities | Corporate Bonds
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	713
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	21
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	95	99
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	5	1
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	808	99
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	26	1
Debt Securities | Foreign Notes
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	5	5
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	5	5
Debt Securities | Capital Trust Notes
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	46
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	1
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	36	37
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	8	7
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	82	37
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	9	7
Equity Securities
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	4	12
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	11
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	1
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	15	$ 12
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	$ 1