LOANS - Corporate Loans Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Loans receivable
Total	$ 667,767	$ 675,883
Loans held at fair value	6,082	6,854
Lease financing
Loans receivable
Total	500	700
Corporate
Loans receivable
Total	396,531	387,044
Total non-accrual	1,877	3,527
Loans held at fair value	6,070	6,840
Corporate | Commercial and industrial
Loans receivable
Total	151,072	156,340
Total non-accrual	1,264	2,795
Corporate | Financial institutions
Loans receivable
Total	98,943	87,689
Total non-accrual	33	92
Corporate | Mortgage and real estate
Loans receivable
Total	73,769	72,038
Total non-accrual	419	505
Corporate | Lease financing
Loans receivable
Total	455	738
Total non-accrual	14	24
Corporate | Other
Loans receivable
Total	66,222	63,399
Total non-accrual	147	111
Corporate | Non-rated private bank loans managed on a delinquency basis
Loans receivable
Current fiscal year	9,984	9,823
One year prior to current fiscal year	8,901	7,121
Two years prior to current fiscal year	5,926	3,533
Three years prior to current fiscal year	2,895	3,674
Four years prior to current fiscal year	2,925	4,300
Prior	8,680	7,942
Revolving line of credit arrangements	0	0
Total	39,311	36,393
Corporate | Corporate loans, net of unearned income
Loans receivable
Current fiscal year	107,868	107,122
One year prior to current fiscal year	30,861	36,513
Two years prior to current fiscal year	24,349	29,628
Three years prior to current fiscal year	18,292	17,059
Four years prior to current fiscal year	11,287	11,340
Prior	35,975	32,195
Revolving line of credit arrangements	161,829	146,347
Total	396,531	387,044
Loans held at fair value	6,070	6,840
Corporate | Investment Grade
Loans receivable
Current fiscal year	73,177	66,625
One year prior to current fiscal year	17,735	20,851
Two years prior to current fiscal year	12,865	17,806
Three years prior to current fiscal year	11,547	8,211
Four years prior to current fiscal year	5,984	4,767
Prior	21,346	17,709
Revolving line of credit arrangements	134,226	115,311
Total	276,880	251,280
Corporate | Investment Grade | Commercial and industrial
Loans receivable
Current fiscal year	42,730	38,398
One year prior to current fiscal year	5,744	7,607
Two years prior to current fiscal year	4,762	5,929
Three years prior to current fiscal year	3,825	3,909
Four years prior to current fiscal year	3,060	2,094
Prior	8,928	8,670
Revolving line of credit arrangements	32,894	25,819
Total	101,943	92,426
Corporate | Investment Grade | Financial institutions
Loans receivable
Current fiscal year	14,096	10,560
One year prior to current fiscal year	1,985	2,964
Two years prior to current fiscal year	1,290	2,106
Three years prior to current fiscal year	1,118	782
Four years prior to current fiscal year	599	681
Prior	2,536	2,030
Revolving line of credit arrangements	67,184	56,239
Total	88,808	75,362
Corporate | Investment Grade | Mortgage and real estate
Loans receivable
Current fiscal year	4,423	6,793
One year prior to current fiscal year	6,013	6,714
Two years prior to current fiscal year	5,421	5,174
Three years prior to current fiscal year	3,630	2,568
Four years prior to current fiscal year	1,801	1,212
Prior	3,561	1,719
Revolving line of credit arrangements	1,341	1,557
Total	26,190	25,737
Corporate | Investment Grade | Other
Loans receivable
Current fiscal year	11,928	10,874
One year prior to current fiscal year	3,993	3,566
Two years prior to current fiscal year	1,392	4,597
Three years prior to current fiscal year	2,974	952
Four years prior to current fiscal year	524	780
Prior	6,321	5,290
Revolving line of credit arrangements	32,807	31,696
Total	59,939	57,755
Corporate | Non-investment grade, accrual | Commercial and industrial
Loans receivable
Current fiscal year	16,814	19,683
One year prior to current fiscal year	2,313	4,794
Two years prior to current fiscal year	2,466	4,645
Three years prior to current fiscal year	2,024	2,883
Four years prior to current fiscal year	1,412	1,182
Prior	3,987	4,533
Revolving line of credit arrangements	18,849	23,400
Total	47,865	61,120
Corporate | Non-investment grade, accrual | Financial institutions
Loans receivable
Current fiscal year	4,471	7,413
One year prior to current fiscal year	399	700
Two years prior to current fiscal year	571	654
Three years prior to current fiscal year	107	274
Four years prior to current fiscal year	74	141
Prior	586	197
Revolving line of credit arrangements	3,894	2,855
Total	10,102	12,234
Corporate | Non-investment grade, accrual | Mortgage and real estate
Loans receivable
Current fiscal year	1,819	1,882
One year prior to current fiscal year	980	1,919
Two years prior to current fiscal year	1,842	2,058
Three years prior to current fiscal year	1,163	1,457
Four years prior to current fiscal year	640	697
Prior	761	837
Revolving line of credit arrangements	644	551
Total	7,849	9,401
Corporate | Non-investment grade, accrual | Other
Loans receivable
Current fiscal year	1,517	1,407
One year prior to current fiscal year	399	918
Two years prior to current fiscal year	594	725
Three years prior to current fiscal year	384	370
Four years prior to current fiscal year	148	186
Prior	383	657
Revolving line of credit arrangements	3,152	1,986
Total	6,577	6,249
Corporate | Non-investment grade, non-accrual | Commercial and industrial
Loans receivable
Current fiscal year	54	260
One year prior to current fiscal year	119	203
Two years prior to current fiscal year	64	192
Three years prior to current fiscal year	104	143
Four years prior to current fiscal year	94	57
Prior	117	223
Revolving line of credit arrangements	712	1,717
Total non-accrual	1,264	2,795
Corporate | Non-investment grade, non-accrual | Financial institutions
Loans receivable
Current fiscal year	0	1
One year prior to current fiscal year	0	0
Two years prior to current fiscal year	0	0
Three years prior to current fiscal year	0	0
Four years prior to current fiscal year	0	0
Prior	0	0
Revolving line of credit arrangements	33	91
Total non-accrual	33	92
Corporate | Non-investment grade, non-accrual | Mortgage and real estate
Loans receivable
Current fiscal year	13	13
One year prior to current fiscal year	10	4
Two years prior to current fiscal year	2	3
Three years prior to current fiscal year	49	18
Four years prior to current fiscal year	10	8
Prior	25	32
Revolving line of credit arrangements	310	427
Total non-accrual	419	505
Corporate | Non-investment grade, non-accrual | Other
Loans receivable
Current fiscal year	19	15
One year prior to current fiscal year	5	3
Two years prior to current fiscal year	19	12
Three years prior to current fiscal year	19	29
Four years prior to current fiscal year	0	2
Prior	90	65
Revolving line of credit arrangements	9	9
Total non-accrual	161	135
Corporate | Non-Investment Grade
Loans receivable
Current fiscal year	24,707	30,674
One year prior to current fiscal year	4,225	8,541
Two years prior to current fiscal year	5,558	8,289
Three years prior to current fiscal year	3,850	5,174
Four years prior to current fiscal year	2,378	2,273
Prior	5,949	6,544
Revolving line of credit arrangements	27,603	31,036
Total	$ 74,270	$ 92,531