EARNINGS PER COMMON SHARE - Computation of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 95	$ 85	$ 189	$ 172
Less: Preferred stock dividends	2	2	4	4
Net Income Available to Common Stockholders	$ 93	$ 83	$ 185	$ 168
Basic weighted average common shares outstanding (in shares)	324,950,162	324,170,177	324,796,294	323,956,752
Net effect of dilutive stock options, warrants and restricted stock (in shares)	999,191	1,559,872	900,927	1,772,440
Diluted weighted average common shares outstanding (in shares)	325,949,353	325,730,049	325,697,221	325,729,192
Earnings per common share:
Basic (in USD per share)	$ 0.29	$ 0.26	$ 0.57	$ 0.52
Diluted (in USD per share)	$ 0.29	$ 0.26	$ 0.57	$ 0.52