EARNINGS PER COMMON SHARE - Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net income	$ 138	$ 111	$ 300	$ 306
Less: Preferred stock dividends	2	2	6	6
Net income available to common stockholders	136	109	294	300
Net income available to common stockholders	$ 136	$ 109	$ 294	$ 300
Basic weighted average common shares outstanding (in shares)	350,910,562	319,512,598	348,868,423	320,023,695
Net effect of dilutive stock options, warrants and restricted stock (in shares)	3,743,917	3,348,329	3,917,702	3,611,960
Diluted weighted average common shares outstanding (in shares)	354,654,479	322,860,927	352,786,125	323,635,655
Earnings per common share:
Basic (in dollars per share)	$ 0.39	$ 0.34	$ 0.84	$ 0.94
Diluted (in dollars per share)	$ 0.38	$ 0.34	$ 0.83	$ 0.93