Derivatives and Hedging Activities - Gain (Loss) from Interest Rate Hedges and Related Hedged Items (Detail) - Fair Value Hedging - Accounted for as hedges - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative [Line Items]
Gains/(losses) on Investments	$ 18	$ 0	$ 15	$ 0
Gains/(losses) on Borrowings and deposits	(79)	(163)	(350)	(468)
Interest rates
Derivative [Line Items]
Gains/(losses) on Investments	427	0	372	0
Gains/(losses) on Borrowings and deposits	(7,820)	(1,528)	(22,629)	(5,459)
Hedged investments
Derivative [Line Items]
Gains/(losses) on Investments	(409)	0	(357)	0
Hedged borrowings and deposits
Derivative [Line Items]
Gains/(losses) on Borrowings and deposits	$ 7,741	$ 1,365	$ 22,279	$ 4,991