v3.22.0.1
Loans - Loans, Level 3 Rollforward (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Loans Receivable [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance $ 2,678 $ 1,890
Net realized gains / (losses) 99 72
Net unrealized gains/(losses) (33) 87
Purchases 272 670
Sales (54) (50)
Settlements (668) (727)
Transfers into level 3 369 836
Transfers out of level 3 (309) (100)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 2,354 2,678
Corporate [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 929 752
Net realized gains / (losses) 31 22
Net unrealized gains/(losses) (34) (22)
Purchases 143 277
Sales (15) (38)
Settlements (251) (125)
Transfers into level 3 127 163
Transfers out of level 3 (93) (100)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 837 929
Commercial real estate [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 1,104 591
Net realized gains / (losses) 45 24
Net unrealized gains/(losses) (21) 60
Purchases 20 334
Sales (6) (5)
Settlements (292) (366)
Transfers into level 3 185 466
Transfers out of level 3 (52) 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 983 1,104
Residential real estate [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 260 221
Net realized gains / (losses) 12 13
Net unrealized gains/(losses) (41) 10
Purchases 58 48
Sales (4) (2)
Settlements (61) (78)
Transfers into level 3 57 48
Transfers out of level 3 (76) 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 205 260
Wealth management and other [Member]    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Beginning Balance 385 326
Net realized gains / (losses) 11 13
Net unrealized gains/(losses) 63 39
Purchases 51 11
Sales (29) (5)
Settlements (64) (158)
Transfers into level 3 0 159
Transfers out of level 3 (88) 0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance $ 329 $ 385