OPERATING SEGMENTS - Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Income (loss) from continuing operations	$ 3,274		$ 3,585		$ 9,945	$ 11,189
Total revenues, net of interest expense	6,953		6,311		21,196	19,946
Total operating expenses	13,250		13,511		40,798	40,370
Provision (benefits) for income taxes	1,116		1,203		3,299	3,824
Held for sale | Mexico and Asia Exit Markets
Segment Reporting Information [Line Items]
Operating expenses, before tax	67	$ 262	114			266
Operating expenses, after tax	46	$ 181	78			188
Sold | India
Segment Reporting Information [Line Items]
Operating expenses, before tax				$ 1,059
Operating expenses, after tax				$ 727
Sold | Taiwan
Segment Reporting Information [Line Items]
Operating expenses, before tax			403
Operating expenses, after tax			284
Operating Segments
Segment Reporting Information [Line Items]
Income (loss) from continuing operations	3,319		3,371		10,116	10,419
Reconciling Items
Segment Reporting Information [Line Items]
Income (loss) from continuing operations	(45)		214		(171)	770
Total revenues, net of interest expense	1		396		22	1,408
Total operating expenses	67		114		262	266
Provision (release) for credit losses	(1)		(17)		7	(37)
Provision (benefits) for income taxes	$ (20)		$ 85		$ (76)	$ 409