LOANS - Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Loans receivable
Total	$ 667,767	$ 675,883
Consumer
Loans receivable
Total	271,236	288,839
Consumer | Residential first mortgages
Loans receivable
Total	43,813	47,778
Consumer | Credit cards
Loans receivable
Total	133,351	129,813
Consumer | Home equity loans
Loans receivable
Total	5,101	7,128
Consumer | Personal, small business and other
Loans receivable
Total	3,158	4,509
Consumer | Less than or equal to 80%
Loans receivable
Total	46,573	49,851
Consumer | Less than or equal to 80% | Residential first mortgages
Loans receivable
Current fiscal year	10,515	11,447
One year prior to current fiscal year	10,206	7,029
Two years prior to current fiscal year	4,372	1,617
Three years prior to current fiscal year	1,300	2,711
Four years prior to current fiscal year	1,986	5,423
Prior	13,271	14,966
Total	41,650	43,193
Consumer | Less than or equal to 80% | Home equity loans (pre-reset)
Loans receivable
Total	2,315	2,876
Consumer | Less than or equal to 80% | Home equity loans (post-reset)
Loans receivable
Total	2,608	3,782
Consumer | Less than or equal to 80% | Home equity loans
Loans receivable
Total	4,923	6,658
Consumer | 80% but less than or equal to 100%
Loans receivable
Total	793	3,185
Consumer | 80% but less than or equal to 100% | Residential first mortgages
Loans receivable
Current fiscal year	474	1,543
One year prior to current fiscal year	75	376
Two years prior to current fiscal year	35	507
Three years prior to current fiscal year	74	269
Four years prior to current fiscal year	27	84
Prior	34	66
Total	719	2,845
Consumer | 80% but less than or equal to 100% | Home equity loans (pre-reset)
Loans receivable
Total	26	50
Consumer | 80% but less than or equal to 100% | Home equity loans (post-reset)
Loans receivable
Total	48	290
Consumer | 80% but less than or equal to 100% | Home equity loans
Loans receivable
Total	74	340
Consumer | Greater than 100%
Loans receivable
Total	51	109
Consumer | Greater than 100% | Residential first mortgages
Loans receivable
Current fiscal year	1	0
One year prior to current fiscal year	0	2
Two years prior to current fiscal year	1	11
Three years prior to current fiscal year	5	4
Four years prior to current fiscal year	2	2
Prior	8	16
Total	17	35
Consumer | Greater than 100% | Home equity loans (pre-reset)
Loans receivable
Total	9	16
Consumer | Greater than 100% | Home equity loans (post-reset)
Loans receivable
Total	25	58
Consumer | Greater than 100% | Home equity loans
Loans receivable
Total	34	74
Consumer | LTV not available
Loans receivable
Total	1,497	1,761
Consumer | LTV not available | Residential first mortgages
Loans receivable
Total	1,427	1,705
Consumer | LTV not available | Home equity loans
Loans receivable
Total	70	56
Consumer | Total
Loans receivable
Total	48,914	54,906
Consumer | Less than 680
Loans receivable
Total	26,714	30,920
Consumer | Less than 680 | Residential first mortgages
Loans receivable
Current fiscal year	201	187
One year prior to current fiscal year	200	150
Two years prior to current fiscal year	140	246
Three years prior to current fiscal year	196	298
Four years prior to current fiscal year	240	323
Prior	1,507	1,708
Total	2,484	2,912
Consumer | Less than 680 | Credit cards
Loans receivable
Total	23,115	26,227
Consumer | Less than 680 | Credit cards | Canada
Loans receivable
Total	517	572
Consumer | Less than 680 | Home equity loans (pre-reset)
Loans receivable
Total	222	292
Consumer | Less than 680 | Home equity loans (post-reset)
Loans receivable
Total	609	1,055
Consumer | Less than 680 | Home equity loans
Loans receivable
Total	831	1,347
Consumer | Less than 680 | Personal, small business and other
Loans receivable
Current fiscal year	59	23
One year prior to current fiscal year	22	79
Two years prior to current fiscal year	42	82
Three years prior to current fiscal year	34	26
Four years prior to current fiscal year	7	10
Prior	120	214
Total	284	434
Consumer | 680 to 760
Loans receivable
Total	67,447	68,634
Consumer | 680 to 760 | Residential first mortgages
Loans receivable
Current fiscal year	3,415	3,741
One year prior to current fiscal year	2,732	1,857
Two years prior to current fiscal year	1,178	655
Three years prior to current fiscal year	431	846
Four years prior to current fiscal year	625	1,368
Prior	3,817	4,133
Total	12,198	12,600
Consumer | 680 to 760 | Credit cards
Loans receivable
Total	52,907	52,778
Consumer | 680 to 760 | Home equity loans (pre-reset)
Loans receivable
Total	836	1,014
Consumer | 680 to 760 | Home equity loans (post-reset)
Loans receivable
Total	989	1,569
Consumer | 680 to 760 | Home equity loans
Loans receivable
Total	1,825	2,583
Consumer | 680 to 760 | Personal, small business and other
Loans receivable
Current fiscal year	201	58
One year prior to current fiscal year	41	106
Two years prior to current fiscal year	53	80
Three years prior to current fiscal year	35	27
Four years prior to current fiscal year	8	9
Prior	179	393
Total	517	673
Consumer | Greater than 760
Loans receivable
Total	85,758	84,224
Consumer | Greater than 760 | Residential first mortgages
Loans receivable
Current fiscal year	7,363	9,052
One year prior to current fiscal year	7,339	5,384
Two years prior to current fiscal year	3,082	1,227
Three years prior to current fiscal year	747	1,829
Four years prior to current fiscal year	1,143	3,799
Prior	7,903	9,105
Total	27,577	30,396
Consumer | Greater than 760 | Credit cards
Loans receivable
Total	55,137	49,767
Consumer | Greater than 760 | Home equity loans (pre-reset)
Loans receivable
Total	1,309	1,657
Consumer | Greater than 760 | Home equity loans (post-reset)
Loans receivable
Total	1,095	1,524
Consumer | Greater than 760 | Home equity loans
Loans receivable
Total	2,404	3,181
Consumer | Greater than 760 | Personal, small business and other
Loans receivable
Current fiscal year	319	95
One year prior to current fiscal year	64	134
Two years prior to current fiscal year	68	84
Three years prior to current fiscal year	37	30
Four years prior to current fiscal year	9	8
Prior	143	529
Total	640	880
Consumer | FICO not available
Loans receivable
Total	5,504	5,450
Consumer | FICO not available | Residential first mortgages
Loans receivable
Total	1,554	1,870
Consumer | FICO not available | Credit cards
Loans receivable
Total	2,192	1,041
Consumer | FICO not available | Home equity loans
Loans receivable
Total	41	17
Consumer | FICO not available | Personal, small business and other
Loans receivable
Total	1,717	2,522
Consumer | Total loans
Loans receivable
Total	$ 185,423	$ 189,228