GOODWILL AND INTANGIBLE ASSETS - Goodwill Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Beginning balance	$ 8,173	$ 7,116
Business acquisitions	15	1,057
Ending balance	8,188	8,173
Consumer Banking
Goodwill [Roll Forward]
Beginning balance	2,673	2,258
Business acquisitions	5	415
Ending balance	2,678	2,673
Commercial Banking
Goodwill [Roll Forward]
Beginning balance	5,500	4,858
Business acquisitions	10	642
Ending balance	$ 5,510	$ 5,500