Loans - Summary of Credit Concentration by Region (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Product Information [Line Items]
Carrying Value	$ 184,829	$ 162,135
Concentration risk percentage	100.00%	100.00%
Americas
Product Information [Line Items]
Concentration risk percentage	81.00%	76.00%
EMEA
Product Information [Line Items]
Concentration risk percentage	15.00%	19.00%
Asia
Product Information [Line Items]
Concentration risk percentage	4.00%	5.00%
Corporate
Product Information [Line Items]
Carrying Value	$ 40,135	$ 37,643
Concentration risk percentage	100.00%	100.00%
Corporate | Americas
Product Information [Line Items]
Concentration risk percentage	57.00%	52.00%
Corporate | EMEA
Product Information [Line Items]
Concentration risk percentage	34.00%	38.00%
Corporate | Asia
Product Information [Line Items]
Concentration risk percentage	9.00%	10.00%
Commercial real estate
Product Information [Line Items]
Carrying Value	$ 28,879	$ 29,000
Concentration risk percentage	100.00%	100.00%
Commercial real estate | Americas
Product Information [Line Items]
Concentration risk percentage	79.00%	82.00%
Commercial real estate | EMEA
Product Information [Line Items]
Concentration risk percentage	16.00%	13.00%
Commercial real estate | Asia
Product Information [Line Items]
Concentration risk percentage	5.00%	5.00%
Residential real estate
Product Information [Line Items]
Carrying Value	$ 23,035	$ 24,674
Concentration risk percentage	100.00%	100.00%
Residential real estate | Americas
Product Information [Line Items]
Concentration risk percentage	96.00%	96.00%
Residential real estate | EMEA
Product Information [Line Items]
Concentration risk percentage	3.00%	2.00%
Residential real estate | Asia
Product Information [Line Items]
Concentration risk percentage	1.00%	2.00%
Securities-based
Product Information [Line Items]
Carrying Value	$ 16,671	$ 16,652
Concentration risk percentage	100.00%	100.00%
Securities-based | Americas
Product Information [Line Items]
Concentration risk percentage	83.00%	77.00%
Securities-based | EMEA
Product Information [Line Items]
Concentration risk percentage	15.00%	16.00%
Securities-based | Asia
Product Information [Line Items]
Concentration risk percentage	2.00%	7.00%
Other collateralized
Product Information [Line Items]
Carrying Value	$ 51,702	$ 38,263
Concentration risk percentage	100.00%	100.00%
Other collateralized | Americas
Product Information [Line Items]
Concentration risk percentage	86.00%	74.00%
Other collateralized | EMEA
Product Information [Line Items]
Concentration risk percentage	12.00%	23.00%
Other collateralized | Asia
Product Information [Line Items]
Concentration risk percentage	2.00%	3.00%
Installment
Product Information [Line Items]
Carrying Value	$ 6,326	$ 3,672
Concentration risk percentage	100.00%	100.00%
Installment | Americas
Product Information [Line Items]
Concentration risk percentage	100.00%	100.00%
Installment | EMEA
Product Information [Line Items]
Concentration risk percentage	0.00%	0.00%
Installment | Asia
Product Information [Line Items]
Concentration risk percentage	0.00%	0.00%
Credit cards
Product Information [Line Items]
Carrying Value	$ 15,820	$ 8,212
Concentration risk percentage	100.00%	100.00%
Credit cards | Americas
Product Information [Line Items]
Concentration risk percentage	100.00%	100.00%
Credit cards | EMEA
Product Information [Line Items]
Concentration risk percentage	0.00%	0.00%
Credit cards | Asia
Product Information [Line Items]
Concentration risk percentage	0.00%	0.00%
Other
Product Information [Line Items]
Carrying Value	$ 2,261	$ 4,019
Concentration risk percentage	100.00%	100.00%
Other | Americas
Product Information [Line Items]
Concentration risk percentage	89.00%	89.00%
Other | EMEA
Product Information [Line Items]
Concentration risk percentage	11.00%	11.00%
Other | Asia
Product Information [Line Items]
Concentration risk percentage	0.00%	0.00%
Technology Media Telecommunications
Product Information [Line Items]
Concentration risk percentage	26.00%	24.00%
Diversified Industrials
Product Information [Line Items]
Concentration risk percentage	18.00%	17.00%
Real estate
Product Information [Line Items]
Concentration risk percentage	11.00%
Healthcare
Product Information [Line Items]
Concentration risk percentage	10.00%	10.00%
Consumer and Retail
Product Information [Line Items]
Concentration risk percentage	10.00%	11.00%
Natural Resources & Utilities
Product Information [Line Items]
Concentration risk percentage		13.00%