SHARE-BASED COMPENSATION - Summary of Activity of Non-Performance-Based & Performance-Based Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Option Activity, Shares
Granted (in shares)	0	0	0
Options assumed pursuant to acquisition of Fidelity (in shares)	576,588
Non-Performance-Based
Stock Option Activity, Shares
Under option, beginning of year (in shares)	0	47,294
Granted (in shares)	0	0
Options assumed pursuant to acquisition of Fidelity (in shares)	576,588
Exercised (in shares)	(189,395)	(47,294)
Forfeited (in shares)	0	0
Under option, end of year (in shares)	387,193	0	47,294
Exercisable at end of year (in shares)	387,193	0
Stock Options Weighted Average Exercise Price
Under option, beginning of year, Weighted-Average Exercise Price (in dollars per share)	$ 0	$ 14.76
Granted, Weighted-Average Exercise Price (in dollars per share)	0	0
Options assumed pursuant to acquisition of Fidelity, Weighted-Average Exercise Price (in dollars per share)	26.62
Exercised, Weighted-Average Exercise Price (in dollars per share)	26.85	14.76
Forfeited, Weighted-Average Exercise Price (in dollars per share)	0	0
Under option, end of year, Weighted-Average Exercise Price (in dollars per share)	26.51	0	$ 14.76
Exercisable at end of year, Weighted-Average Exercise Price (in dollars per share)	$ 26.51	$ 0
Stock Option Activity, Additional Disclosures
Under option, end of year, Weighted Average Contractual Term	1 year 10 months 28 days	0 years
Exercisable at end of year, Weighted Average Contractual Term	1 year 10 months 28 days	0 years
Exercised, Aggregate Intrinsic Value	$ 2,437	$ 653
Under option, end of year, Aggregate Intrinsic Value	6,208	0
Exercisable at end of year, Aggregate Intrinsic Value	$ 6,208	$ 0
Performance-Based
Stock Option Activity, Shares
Under option, beginning of year (in shares)	7,711	37,013
Granted (in shares)	0	0
Options assumed pursuant to acquisition of Fidelity (in shares)	0
Exercised (in shares)	(7,711)	(29,014)
Forfeited (in shares)	0	(288)
Under option, end of year (in shares)	0	7,711	37,013
Exercisable at end of year (in shares)	0	7,711
Stock Options Weighted Average Exercise Price
Under option, beginning of year, Weighted-Average Exercise Price (in dollars per share)	$ 6.94	$ 7.36
Granted, Weighted-Average Exercise Price (in dollars per share)	0	0
Options assumed pursuant to acquisition of Fidelity, Weighted-Average Exercise Price (in dollars per share)	0
Exercised, Weighted-Average Exercise Price (in dollars per share)	6.94	7.47
Forfeited, Weighted-Average Exercise Price (in dollars per share)	0	7.47
Under option, end of year, Weighted-Average Exercise Price (in dollars per share)	0	6.94	$ 7.36
Exercisable at end of year, Weighted-Average Exercise Price (in dollars per share)	$ 0	$ 6.94
Stock Option Activity, Additional Disclosures
Under option, end of year, Weighted Average Contractual Term	0 years	1 month 9 days
Exercisable at end of year, Weighted Average Contractual Term	0 years	1 month 9 days
Exercised, Aggregate Intrinsic Value	$ 229	$ 217
Forfeited, Aggregate Intrinsic Value
Under option, end of year, Aggregate Intrinsic Value	0	308
Exercisable at end of year, Aggregate Intrinsic Value	$ 0	$ 308