Loans - Summary of Weighted Average of Significant Unobservable Inputs (Detail) $ in Millions	Sep. 30, 2022 USD ($) yr	Dec. 31, 2021 USD ($) yr
Loans at fair value | $	$ 8,250	$ 10,769
Level 3
Loans at fair value | $	2,058	2,354
Corporate
Loans at fair value | $	1,844	2,492
Corporate | Level 3
Loans at fair value | $	743	837
Commercial real estate
Loans at fair value | $	1,277	1,588
Commercial real estate | Level 3
Loans at fair value | $	845	983
Residential real estate
Loans at fair value | $	257	320
Residential real estate | Level 3
Loans at fair value | $	95	205
Wealth management and other | Level 3
Loans at fair value | $	$ 375	$ 329
Minimum | Yield | Corporate | Level 3
Measurement input	0.020	0.015
Minimum | Yield | Commercial real estate | Level 3
Measurement input	0.014	0.032
Minimum | Yield | Residential real estate | Level 3
Measurement input	0.038	0.021
Minimum | Yield | Wealth management and other | Level 3
Measurement input	0.057	0.036
Minimum | Recovery rate | Corporate | Level 3
Measurement input	0.150	0.150
Minimum | Recovery rate | Commercial real estate | Level 3
Measurement input	0.036	0.041
Minimum | Duration (years) | Corporate | Level 3
Measurement input	0.3	0.9
Minimum | Duration (years) | Commercial real estate | Level 3
Measurement input	0.3	0.4
Minimum | Duration (years) | Residential real estate | Level 3
Measurement input	0.3	0.1
Minimum | Duration (years) | Wealth management and other | Level 3
Measurement input	2.9	2.9
Maximum | Yield | Corporate | Level 3
Measurement input	0.250	0.556
Maximum | Yield | Commercial real estate | Level 3
Measurement input	0.270	0.187
Maximum | Yield | Residential real estate | Level 3
Measurement input	0.170	0.200
Maximum | Yield | Wealth management and other | Level 3
Measurement input	0.130	0.187
Maximum | Recovery rate | Corporate | Level 3
Measurement input	0.950	0.920
Maximum | Recovery rate | Commercial real estate | Level 3
Measurement input	0.235	0.995
Maximum | Duration (years) | Corporate | Level 3
Measurement input	3.5	6.8
Maximum | Duration (years) | Commercial real estate | Level 3
Measurement input	4.8	4.0
Maximum | Duration (years) | Residential real estate | Level 3
Measurement input	7.3	2.4
Maximum | Duration (years) | Wealth management and other | Level 3
Measurement input	5.4	5.5
Weighted Average | Yield | Corporate | Level 3
Measurement input	0.107	0.149
Weighted Average | Yield | Commercial real estate | Level 3
Measurement input	0.141	0.126
Weighted Average | Yield | Residential real estate | Level 3
Measurement input	0.138	0.161
Weighted Average | Yield | Wealth management and other | Level 3
Measurement input	0.087	0.071
Weighted Average | Recovery rate | Corporate | Level 3
Measurement input	0.436	0.408
Weighted Average | Recovery rate | Commercial real estate | Level 3
Measurement input	0.168	0.414
Weighted Average | Duration (years) | Corporate | Level 3
Measurement input	2.6	2.7
Weighted Average | Duration (years) | Commercial real estate | Level 3
Measurement input	2.1	1.7
Weighted Average | Duration (years) | Residential real estate | Level 3
Measurement input	2.4	1.0
Weighted Average | Duration (years) | Wealth management and other | Level 3
Measurement input	3.9	3.6