ACQUISITIONS - Schedule of Pro Forma Information (Details) - Investors Acquisition - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Net income	$ 658		$ 609	$ 1,741	$ 1,754
Share-based compensation		$ 122
Net interest income
Business Acquisition [Line Items]
Net income	1,665		1,352	4,531	4,004
Noninterest income
Business Acquisition [Line Items]
Net income	$ 512		$ 530	$ 1,550	$ 1,559