SHARE-BASED COMPENSATION - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted Average Exercise Price Per Share
Exercised, weighted average exercise price per share (in dollars per share)	$ 17.43
2017 LTIP
Weighted Average Exercise Price Per Share
Beginning balance (in dollars per share)	17.50	$ 17.45
Granted (in dollars per share)	23.88	17.58
Forfeited (in dollars per share)	18.42	17.92
Ending balance (in dollars per share)	19.12	$ 17.50	$ 17.45
Options exercisable (in dollars per share)	$ 17.65
Options outstanding, Weighted Average Remaining Contractual Term (in years)	8 years 8 months 26 days	9 years 5 months 19 days	9 years 11 months 19 days
Options exercisable, Weighted Average Remaining Contractual Term (in years)	8 years 29 days	0 years
Options outstanding, Aggregate Intrinsic Value	$ 112,915,000		$ 8,331,000
Options exercisable, Aggregate Intrinsic Value	$ 8,512
2017 LTIP | Time Vesting
Shares Under Option
Beginning balance (in shares)	11,230,168	5,110,747
Granted (in shares)	3,677,076	6,753,659
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	184,147
Forfeited (in shares)	(639,356)	(634,238)
Ending balance (in shares)	14,083,741	11,230,168	5,110,747
Options exercisable (in shares)	878,225
Weighted Average Exercise Price Per Share
Share based compensation expense	$ 44,464,000	$ 18,491,000	$ 0
2017 LTIP | Performance Based Vesting
Shares Under Option
Beginning balance (in shares)	73,639	0
Granted (in shares)	0	95,953
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	0
Forfeited (in shares)	(73,639)	(22,314)
Ending balance (in shares)	0	73,639	0
Options exercisable (in shares)	0