CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) - Change in Each Component of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Change in accumulated other comprehensive income (loss)
Balance, beginning of period			$ 202,672
Balance, end of period	$ 199,117	$ 201,610	199,117	$ 201,610
Discontinued Operations, Held-for-sale | Australia Consumer Banking Business
Change in accumulated other comprehensive income (loss)
Loss on sale of business, foreign currency translation adjustments, after-tax			470
Loss on sale of business, foreign currency translation adjustments			620
Net unrealized gains (losses) on debt securities
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(6,392)	1,061	(614)	3,320
Other comprehensive income before reclassifications	(595)	(204)	(6,490)	(2,101)
Increase (decrease) due to amounts reclassified from AOCI	15	(75)	132	(437)
Total other comprehensive income	(580)	(279)	(6,358)	(2,538)
Balance, end of period	(6,972)	782	(6,972)	782
Debt valuation adjustment (DVA)
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	1,573	(1,523)	(1,187)	(1,419)
Other comprehensive income before reclassifications	874	(138)	3,635	(295)
Increase (decrease) due to amounts reclassified from AOCI	(2)	56	(3)	109
Total other comprehensive income	872	(82)	3,632	(186)
Balance, end of period	2,445	(1,605)	2,445	(1,605)
Cash flow hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(2,106)	864	101	1,593
Other comprehensive income before reclassifications	(870)	2	(2,709)	(318)
Increase (decrease) due to amounts reclassified from AOCI	107	(203)	(261)	(612)
Total other comprehensive income	(763)	(201)	(2,970)	(930)
Balance, end of period	(2,869)	663	(2,869)	663
Benefit plans
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(5,770)	(6,063)	(5,852)	(6,864)
Other comprehensive income before reclassifications	5	84	26	773
Increase (decrease) due to amounts reclassified from AOCI	32	51	93	163
Total other comprehensive income	37	135	119	936
Balance, end of period	(5,733)	(5,928)	(5,733)	(5,928)
Foreign currency translation adjustment (CTA), net of hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(32,810)	(29,392)	(31,166)	(28,641)
Other comprehensive income before reclassifications	(2,423)	(1,325)	(4,412)	(2,076)
Increase (decrease) due to amounts reclassified from AOCI	24	13	369	13
Total other comprehensive income	(2,399)	(1,312)	(4,043)	(2,063)
Balance, end of period	(35,209)	(30,704)	(35,209)	(30,704)
Excluded component of fair value hedges
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	10	(67)	(47)	(47)
Other comprehensive income before reclassifications	31	7	81	(14)
Increase (decrease) due to amounts reclassified from AOCI	(1)	1	6	2
Total other comprehensive income	30	8	87	(12)
Balance, end of period	40	(59)	40	(59)
Accumulated other comprehensive income (loss)
Change in accumulated other comprehensive income (loss)
Balance, beginning of period	(45,495)	(35,120)	(38,765)	(32,058)
Other comprehensive income before reclassifications	(2,978)	(1,574)	(9,869)	(4,031)
Increase (decrease) due to amounts reclassified from AOCI	175	(157)	336	(762)
Total other comprehensive income	(2,803)	(1,731)	(9,533)	(4,793)
Balance, end of period	$ (48,298)	$ (36,851)	$ (48,298)	$ (36,851)