GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2026 USD ($)
Goodwill by business segment
Balance, December 31, 2025	$ 5,997
Cadence acquisition	3,497
Other activity	33
Balance, March 31, 2026	9,527
Consumer & Regional Banking | Operating Segments
Goodwill by business segment
Balance, December 31, 2025	3,855
Cadence acquisition	2,597
Other activity	0
Balance, March 31, 2026	6,452
Commercial Banking | Operating Segments
Goodwill by business segment
Balance, December 31, 2025	2,142
Cadence acquisition	900
Other activity	33
Balance, March 31, 2026	$ 3,075