v3.20.4
Loans - Summary of Weighted Average of Significant Unobservable Inputs (Detail)
$ in Millions
Dec. 31, 2020
USD ($)
yr
Dec. 31, 2019
USD ($)
yr
Loans receivable at fair value | $ $ 13,625 $ 14,386
Level 3 [Member]    
Loans receivable at fair value | $ 2,678 1,890
Corporate [Member]    
Loans receivable at fair value | $ 2,751 3,224
Corporate [Member] | Level 3 [Member]    
Loans receivable at fair value | $ 929 752
Commercial real estate [Member]    
Loans receivable at fair value | $ 1,961 1,876
Commercial real estate [Member] | Level 3 [Member]    
Loans receivable at fair value | $ 1,104 591
Residential real estate [Member]    
Loans receivable at fair value | $ 494 792
Residential real estate [Member] | Level 3 [Member]    
Loans receivable at fair value | $ 260 221
Wealth management and other [Member] | Level 3 [Member]    
Loans receivable at fair value | $ $ 385 $ 326
Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.011 0.019
Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.045 0.070
Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.020 0.011
Minimum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.028 0.039
Minimum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.150 0.135
Minimum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.030 0.059
Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 1.5 3.7
Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.3 0.2
Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.6 1.1
Minimum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.9 1.6
Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.452 0.263
Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.193 0.160
Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.140 0.140
Maximum [Member] | Fair Value Unobservable Inputs, Yield [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.187 0.160
Maximum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.580 0.780
Maximum [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.998 0.852
Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 5.3 5.8
Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 4.8 5.3
Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 2.6 4.8
Maximum [Member] | Fair Value Unobservable Inputs, Duration [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 5.5 6.7
Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.124 0.095
Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.110 0.093
Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.121 0.115
Weighted Average [Member] | Fair Value Unobservable Inputs, Yield [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.080 0.099
Weighted Average [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.310 0.444
Weighted Average [Member] | Fair Value Unobservable Inputs, Recovery Rate [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 0.665 0.486
Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member] | Corporate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 3.4 3.9
Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member] | Commercial real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 2.6 3.5
Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member] | Residential real estate [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 1.7 4.0
Weighted Average [Member] | Fair Value Unobservable Inputs, Duration [Member] | Wealth management and other [Member] | Level 3 [Member]    
Loans Receivable, Measurement Input 4.1 3.7