Derivatives and Hedging Activities - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Derivative [Line Items]
Gross fair value of derivatives included in derivative assets	$ 9,700,000,000		$ 9,700,000,000		$ 10,080,000,000.00
Gross fair value of derivatives included in derivative liabilities	12,570,000,000		12,570,000,000		12,710,000,000
Notional amount	42,878,657,000,000		42,878,657,000,000		38,061,442,000,000
Net notional purchased protection	67,080,000,000.00		67,080,000,000.00		50,830,000,000
Net gains (losses) on hedges and related available-for-sale securities	0	$ 3,000,000	0	$ (25,000,000)
Gains (losses) related to hedges		189,000,000		425,000,000
Gains (losses) on related hedged available-for-sale securities		$ (186,000,000)		$ (450,000,000)
Foreign currency denominated debt designated as hedges	$ 26,350,000,000		$ 26,350,000,000		$ 21,460,000,000
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]	Trading assets (at fair value and includes $97,406 and $40,143 pledged as collateral)		Trading assets (at fair value and includes $97,406 and $40,143 pledged as collateral)		Trading assets (at fair value and includes $97,406 and $40,143 pledged as collateral)
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Trading assets (at fair value and includes $97,406 and $40,143 pledged as collateral)		Trading assets (at fair value and includes $97,406 and $40,143 pledged as collateral)
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]	Trading liabilities		Trading liabilities		Trading liabilities
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Trading liabilities		Trading liabilities		Trading liabilities
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Market making, Other principal transactions	Market making, Other principal transactions
Other principal transactions
Derivative [Line Items]
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Market making, Other principal transactions	Market making, Other principal transactions
Market making
Derivative [Line Items]
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Market making, Other principal transactions	Market making, Other principal transactions
Written Credit Derivative
Derivative [Line Items]
Notional amount	$ 565,330,000,000		$ 565,330,000,000		$ 528,310,000,000
Purchased Credit Derivative
Derivative [Line Items]
Notional amount	632,410,000,000		632,410,000,000		579,140,000,000
Accounted for as hedges
Derivative [Line Items]
Notional amount	253,140,000,000		253,140,000,000		270,644,000,000
Amortized cost of investments	15,820,000,000		15,820,000,000		11,490,000,000
Unsecured long-term borrowings | Accounted for as hedges
Derivative [Line Items]
Cumulative hedging adjustments for items no longer designated in a hedging relationship	50,000,000		50,000,000		111,000,000
Cumulative hedging adjustment	$ (5,850,000,000)		$ (5,850,000,000)		$ 5,090,000,000.00