EARNINGS PER COMMON SHARE - Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income	$ 53	$ 93
Less: Preferred stock dividends	2	2
Net income available to common stockholders	51	91
Net income available to common stockholders	$ 51	$ 91
Basic weighted average common shares outstanding (in shares)	344,352,853	320,975,209
Net effect of dilutive stock options, warrants and restricted stock (in shares)	4,573,193	3,769,650
Diluted weighted average common shares outstanding (in shares)	348,926,046	324,744,859
Earnings per common share:
Basic (in dollars per share)	$ 0.15	$ 0.28
Diluted (in dollars per share)	$ 0.15	$ 0.28