Securities - Summary of Held-to-Maturity and Available-for-Sale Securities Having Continuous Unrealized Loss Position (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	$ 3,821	$ 1,846
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	181	44
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	2,594	1,683
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	667	72
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	6,415	3,529
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	848	116
Debt Securities \| U.S. Treasury Obligations
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	1,476	45
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	5
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	1,476	45
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	5
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	394	317
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	43	7
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	1,012	185
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	300	8
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	1,406	502
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	343	15
Debt Securities \| GSE Certificates
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	572	846
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	62	28
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	371	293
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	109	17
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	943	1,139
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	171	45
Debt Securities \| GSE CMOs
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	448	491
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	41	8
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	838	926
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	235	37
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	1,286	1,417
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	276	45
Debt Securities \| Asset-backed Securities
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	125	130
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	2	1
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Fair Value	224	135
Temporarily Impaired Available-for-Sale Securities, Twelve Months or Longer Unrealized Loss	8	2
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	349	265
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	10	3
Debt Securities \| Municipal Bonds
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	11
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	18	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	720
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Unrealized Loss	27
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	4	1
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	815	99
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	31	1
Debt Securities \| Foreign Notes
Schedule of Investments [Line Items]
Temporarily Impaired Available-for-Sale Securities, Less than Twelve Months Fair Value	25	5
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	25	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	2
Temporarily Impaired Available-for-Sale Securities, Total Fair Value	15	$ 12
Temporarily Impaired Available-for-Sale Securities, Total Unrealized Loss	$ 2

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