ALLOWANCE FOR CREDIT LOSSES - Allowance for Credit Losses Roll Forward by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Allowance for credit losses
Allowance for credit losses on loans (ACLL) at beginning of period	$ 19,123	$ 18,216	$ 18,574	$ 18,145
Charge-offs	(2,726)	(2,609)	(8,375)	(8,014)
Recoveries	512	437	1,468	1,256
Replenishment of NCLs	2,214	2,172	6,907	6,758
Net reserve builds (releases)	(10)	254	466	636
Net specific reserve builds (releases)	55	(44)	(76)	(231)
Other	38	(93)	242	(217)
ACLL at end of period	19,206	18,356	19,206	18,356
ACLL
Collectively evaluated	18,939		18,939		$ 18,221
Individually evaluated	267		267		340
Total ACLL	19,206	18,356	19,206	18,356	18,574
Loans, net of unearned income
Collectively evaluated	723,697		723,697		684,812
Individually evaluated	2,204		2,204		1,511
Held at fair value	7,896		7,896		8,040
Total loans, net of unearned income	733,905		733,905		694,488
Credit deteriorated assets		37		46
Purchased credit deteriorated
ACLL
Purchased credit deteriorated	0		0		13
Loans, net of unearned income
Purchased credit deteriorated	108		108		125
Corporate loans
Allowance for credit losses
Allowance for credit losses on loans (ACLL) at beginning of period	3,023	2,484	2,556	2,714
Charge-offs	(114)	(113)	(376)	(420)
Recoveries	22	39	53	74
Replenishment of NCLs	92	74	323	346
Net reserve builds (releases)	(76)	143	468	115
Net specific reserve builds (releases)	54	(40)	(77)	(229)
Other	0	4	54	(9)
ACLL at end of period	3,001	2,591	3,001	2,591
ACLL
Collectively evaluated	2,774		2,774		2,254
Individually evaluated	227		227		302
Total ACLL	3,001	2,591	3,001	2,591	2,556
Loans, net of unearned income
Collectively evaluated	325,336		325,336		292,250
Individually evaluated	2,071		2,071		1,377
Held at fair value	7,870		7,870		7,759
Total loans, net of unearned income	335,277		335,277		301,386
Corporate loans | Purchased credit deteriorated
ACLL
Purchased credit deteriorated	0		0		0
Loans, net of unearned income
Purchased credit deteriorated	0		0		0
Consumer loans
Allowance for credit losses
Allowance for credit losses on loans (ACLL) at beginning of period	16,100	15,732	16,018	15,431
Charge-offs	(2,612)	(2,496)	(7,999)	(7,594)
Recoveries	490	398	1,415	1,182
Replenishment of NCLs	2,122	2,098	6,584	6,412
Net reserve builds (releases)	66	111	(2)	521
Net specific reserve builds (releases)	1	(4)	1	(2)
Other	38	(97)	188	(208)
ACLL at end of period	16,205	15,765	16,205	15,765
ACLL
Collectively evaluated	16,165		16,165		15,967
Individually evaluated	40		40		38
Total ACLL	16,205	$ 15,765	16,205	$ 15,765	16,018
Loans, net of unearned income
Collectively evaluated	398,361		398,361		392,562
Individually evaluated	133		133		134
Held at fair value	26		26		281
Total loans, net of unearned income	398,628		398,628		393,102
Consumer loans | Purchased credit deteriorated
ACLL
Purchased credit deteriorated	0		0		13
Loans, net of unearned income
Purchased credit deteriorated	$ 108		$ 108		$ 125