ACQUISITIONS - Schedule of Acquisition and Integration Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Provision for credit losses	$ 90	$ (48)	$ 303	$ (308)
Salaries and employee benefits	639	509	1,916	1,581
Outside services	172	144	530	420
Other operating expense	165	124	428	308
Total acquisition-related costs	813	$ 681	1,827	$ 2,293
Investors Acquisition | Acquisition-related Costs
Business Acquisition [Line Items]
Provision for credit losses	0		145
Salaries and employee benefits	12		73
Outside services	12		48
Mark-to-market losses on LHFS portfolio	0		31
Other operating expense	8		10
Total acquisition-related costs	$ 32		$ 307