LOANS - Performance of Modified Consumer Loans (Details) - Consumer $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
In North America offices
Loans receivable
Total modified loans balance	$ 1,238
Gross credit losses	205
In North America offices | Current
Loans receivable
Total modified loans balance	836
In North America offices | 30–89 days past due
Loans receivable
Total modified loans balance	203
In North America offices | 90+ days past due
Loans receivable
Total modified loans balance	199
Outside U.S.
Loans receivable
Total modified loans balance	404
Gross credit losses	5
Outside U.S. | Current
Loans receivable
Total modified loans balance	392
Outside U.S. | 30–89 days past due
Loans receivable
Total modified loans balance	8
Outside U.S. | 90+ days past due
Loans receivable
Total modified loans balance	4
Residential first mortgages | In North America offices
Loans receivable
Total modified loans balance	164
Gross credit losses	0
Residential first mortgages | In North America offices | Current
Loans receivable
Total modified loans balance	70
Residential first mortgages | In North America offices | 30–89 days past due
Loans receivable
Total modified loans balance	22
Residential first mortgages | In North America offices | 90+ days past due
Loans receivable
Total modified loans balance	72
Residential first mortgages | Outside U.S.
Loans receivable
Total modified loans balance	334
Gross credit losses	0
Residential first mortgages | Outside U.S. | Current
Loans receivable
Total modified loans balance	331
Residential first mortgages | Outside U.S. | 30–89 days past due
Loans receivable
Total modified loans balance	2
Residential first mortgages | Outside U.S. | 90+ days past due
Loans receivable
Total modified loans balance	1
Home equity loans | In North America offices
Loans receivable
Total modified loans balance	21
Gross credit losses	0
Home equity loans | In North America offices | Current
Loans receivable
Total modified loans balance	14
Home equity loans | In North America offices | 30–89 days past due
Loans receivable
Total modified loans balance	1
Home equity loans | In North America offices | 90+ days past due
Loans receivable
Total modified loans balance	6
Total credit cards | In North America offices
Loans receivable
Total modified loans balance	1,039
Gross credit losses	204
Total credit cards | In North America offices | Current
Loans receivable
Total modified loans balance	740
Total credit cards | In North America offices | 30–89 days past due
Loans receivable
Total modified loans balance	179
Total credit cards | In North America offices | 90+ days past due
Loans receivable
Total modified loans balance	120
Total credit cards | Outside U.S.
Loans receivable
Total modified loans balance	43
Gross credit losses	4
Total credit cards | Outside U.S. | Current
Loans receivable
Total modified loans balance	37
Total credit cards | Outside U.S. | 30–89 days past due
Loans receivable
Total modified loans balance	3
Total credit cards | Outside U.S. | 90+ days past due
Loans receivable
Total modified loans balance	3
Personal, small business and other | In North America offices
Loans receivable
Total modified loans balance	14
Gross credit losses	1
Personal, small business and other | In North America offices | Current
Loans receivable
Total modified loans balance	12
Personal, small business and other | In North America offices | 30–89 days past due
Loans receivable
Total modified loans balance	1
Personal, small business and other | In North America offices | 90+ days past due
Loans receivable
Total modified loans balance	1
Personal, small business and other | Outside U.S.
Loans receivable
Total modified loans balance	27
Gross credit losses	1
Personal, small business and other | Outside U.S. | Current
Loans receivable
Total modified loans balance	24
Personal, small business and other | Outside U.S. | 30–89 days past due
Loans receivable
Total modified loans balance	3
Personal, small business and other | Outside U.S. | 90+ days past due
Loans receivable
Total modified loans balance	$ 0