DERIVATIVES - Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) recognized in AOCI on derivative	$ 9	$ (1,737)
Net pretax change in cash flow hedges included within AOCI	479	(2,022)
Cash flow hedge gain expected to be reclassified from AOCI within 12 months	$ (1,400)
Maximum length of time hedged in cash flow hedge	13 years
Interest rate contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) recognized in AOCI on derivative	$ 21	(1,760)
Foreign exchange contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) recognized in AOCI on derivative	(12)	23
Other revenue
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	(1)	(1)
Other revenue | Interest rate contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	0	0
Other revenue | Foreign exchange contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	(1)	(1)
Net interest income
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	(469)	286
Net interest income | Interest rate contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	(469)	286
Net interest income | Foreign exchange contracts
Pretax change in accumulated other comprehensive income (loss)
Amount of gain (loss) reclassified from AOCI to earnings	$ 0	$ 0