v3.21.2
Loans - Loans, Level 3 Rollforward (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 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 $ 2,531 $ 2,753 $ 2,678 $ 1,890
Net realized gains / (losses) 21 16 47 37
Net unrealized gains/(losses) 22 10 (11) (53)
Purchases 35 58 68 397
Sales       (7)
Settlements (249) (173) (377) (379)
Transfers into level 3 51 163 94 787
Transfers out of level 3 (182) (168) (270) (13)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 2,229 2,659 2,229 2,659
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 976 1,044 929 752
Net realized gains / (losses) 8 4 16 10
Net unrealized gains/(losses) 3 (1) (8) (17)
Purchases 32 37 51 64
Sales       (7)
Settlements (136) (60) (133) (79)
Transfers into level 3 50 83 94 229
Transfers out of level 3 (81) (168) (97) (13)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 852 939 852 939
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 1,028 1,063 1,104 591
Net realized gains / (losses) 7 7 13 16
Net unrealized gains/(losses)   (13) (18) (37)
Purchases 3 16 17 285
Settlements (68) (47) (148) (171)
Transfers into level 3 1 58   400
Transfers out of level 3 (51)   (48)  
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 920 1,084 920 1,084
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 176 260 260 221
Net realized gains / (losses) 3 2 6 1
Net unrealized gains/(losses) (19) 15 (24) 1
Purchases   5   42
Settlements (17) (15) (28) (39)
Transfers into level 3   1   42
Transfers out of level 3 (25)   (96)  
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance 118 268 118 268
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 351 386 385 326
Net realized gains / (losses) 3 3 12 10
Net unrealized gains/(losses) 38 9 39  
Purchases       6
Settlements (28) (51) (68) (90)
Transfers into level 3   21   116
Transfers out of level 3 (25)   (29)  
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value, Ending Balance $ 339 $ 368 $ 339 $ 368