EMPLOYEE BENEFIT PLANS - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Remaining Life
Unrecognized compensation costs related to stock options	$ 1
Stock Options
Number of Options
Outstanding at the beginning of the period (in shares)	912,531
Exercised (in shares)	(293,581)	(108,488)
Outstanding at the end of the period (in shares)	618,950
Vested and expected to vest at the end of the period (in shares)	618,950
Exercisable at the end of the period (in shares)	422,932
Weighted Average Exercise Price Per Share
Outstanding at the beginning of the period (in dollars per share)	$ 22.51
Exercised (in dollars per share)	20.68
Outstanding at the end of the period (in dollars per share)	23.38
Vested and expected to vest at the end of the period (in dollars per share)	23.38
Exercisable at the end of the period (in dollars per share)	$ 21.10
Aggregate Intrinsic Value
Outstanding at the end of the period	$ 27
Vested and expected to vest at the end of the period	27
Exercisable at the end of the period	$ 19
Weighted Average Remaining Life
Outstanding at the end of the period	6 years 8 months 12 days
Vested and expected to vest at the end of the period	6 years 8 months 12 days
Exercisable at the end of the period	6 years 3 months 18 days
Exercised (in shares)	293,581	108,488
Aggregate Intrinsic value of awards exercised	$ 10	$ 1
Period for recognition of unrecognized compensation costs	1 year