LOANS - Consumer Loans Gross Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 2,726	$ 2,609	$ 8,375	$ 8,014
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 2,612	$ 2,496	7,999	7,594
Consumer loans | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Current year			0	0
Prior year			5	1
Two years prior			3	0
Three years prior			12	0
Four years prior			4	0
Prior			43	27
Total			67	28
Consumer loans | Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total			5	7
Consumer loans | Home equity line of credit (pre-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			4	5
Consumer loans | Home equity line of credit (post-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			1	1
Consumer loans | Home equity term loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			0	1
Consumer loans | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Total			7,034	6,787
Consumer loans | Revolving loans converted to term loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			230	188
Consumer loans | Total credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Total			7,264	6,975
Consumer loans | Personal, small business and other
Financing Receivable, Credit Quality Indicator [Line Items]
Current year			129	101
Prior year			190	152
Two years prior			129	131
Three years prior			73	51
Four years prior			29	20
Prior			113	129
Total			$ 663	$ 584