LOANS - Consumer Loans Outside of North America (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Loans receivable
Total loans	$ 689,362	$ 657,221
Consumer
Loans receivable
Total loans	389,197	368,067
Consumer | 30–89 days past due
Loans receivable
Total loans	3,259	2,372
Consumer | 90+ days past due
Loans receivable
Total loans	3,233	2,153
In offices outside North America | Consumer
Loans receivable
Total loans	$ 76,039	$ 79,053
NCL ratio	1.58%	0.91%
In offices outside North America | Consumer | 30–89 days past due
Loans receivable
Total loans	$ 364	$ 314
Past due ratio	0.62%	0.51%
In offices outside North America | Consumer | 90+ days past due
Loans receivable
Total loans	$ 336	$ 265
Past due ratio	0.57%	0.43%
In offices outside North America | Consumer | Classifiably managed
Loans receivable
Total loans	$ 17,007	$ 17,762
In offices outside North America | Consumer | FICO Score, Delinquency Managed Loans
Loans receivable
Total loans	59,032	61,291
In offices outside North America | Consumer | Classifiably managed
Loans receivable
Total loans	77,500	80,500
In offices outside North America | Consumer | Residential first mortgages
Loans receivable
Total loans	$ 26,426	$ 28,114
NCL ratio	0.06%	0.10%
In offices outside North America | Consumer | Residential first mortgages | 30–89 days past due
Loans receivable
Total loans	$ 48	$ 62
Past due ratio	0.18%	0.22%
In offices outside North America | Consumer | Residential first mortgages | 90+ days past due
Loans receivable
Total loans	$ 69	$ 106
Past due ratio	0.26%	0.38%
In offices outside North America | Consumer | Residential first mortgages | Classifiably managed
Loans receivable
Total loans	$ 0	$ 0
In offices outside North America | Consumer | Residential first mortgages | FICO Score, Delinquency Managed Loans
Loans receivable
Total loans	26,426	28,114
In offices outside North America | Consumer | Residential first mortgages | Global Wealth Management Business
Loans receivable
Total loans	19,900	19,800
In offices outside North America | Consumer | Credit cards
Loans receivable
Total loans	$ 14,233	$ 12,955
NCL ratio	5.87%	3.18%
In offices outside North America | Consumer | Credit cards | 30–89 days past due
Loans receivable
Total loans	$ 209	$ 147
Past due ratio	1.47%	1.13%
In offices outside North America | Consumer | Credit cards | 90+ days past due
Loans receivable
Total loans	$ 227	$ 149
Past due ratio	1.59%	1.15%
In offices outside North America | Consumer | Credit cards | Classifiably managed
Loans receivable
Total loans	$ 0	$ 0
In offices outside North America | Consumer | Credit cards | FICO Score, Delinquency Managed Loans
Loans receivable
Total loans	14,233	12,955
In offices outside North America | Consumer | Personal, small business and other
Loans receivable
Total loans	$ 35,380	$ 37,984
NCL ratio	1.03%	0.76%
In offices outside North America | Consumer | Personal, small business and other | Internal Investment Grade
Loans receivable
Percentage internal risk rating	92.00%	98.00%
In offices outside North America | Consumer | Personal, small business and other | 30–89 days past due
Loans receivable
Total loans	$ 107	$ 105
Past due ratio	0.58%	0.52%
In offices outside North America | Consumer | Personal, small business and other | 90+ days past due
Loans receivable
Total loans	$ 40	$ 10
Past due ratio	0.22%	0.05%
In offices outside North America | Consumer | Personal, small business and other | Classifiably managed
Loans receivable
Total loans	$ 17,007	$ 17,762
In offices outside North America | Consumer | Personal, small business and other | FICO Score, Delinquency Managed Loans
Loans receivable
Total loans	$ 18,373	$ 20,222
In offices outside North America | Consumer | Personal, small business and other | Global Wealth Management Business | Internal Investment Grade
Loans receivable
Percentage internal risk rating	74.00%	94.00%
In offices outside North America | Consumer | Personal, small business and other | Global Wealth Management Business | Classifiably managed
Loans receivable
Total loans	$ 24,900	$ 26,600