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, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Option Activity, Shares
Granted (in shares)	0	0	0
Non-Performance-Based
Stock Option Activity, Shares
Under option, beginning of year (in shares)	47,294	58,603
Granted (in shares)	0	0
Exercised (in shares)	(47,294)	(11,309)
Forfeited (in shares)	0	0
Under option, end of year (in shares)	0	47,294	58,603
Exercisable at end of year (in shares)	0	47,294
Stock Options Weighted Average Exercise Price
Under option, beginning of year, Weighted-Average Exercise Price (in dollars per share)	$ 14.76	$ 14.76
Granted, Weighted-Average Exercise Price (in dollars per share)	0.00	0.00
Exercised, Weighted-Average Exercise Price (in dollars per share)	14.76	14.76
Forfeited, Weighted-Average Exercise Price (in dollars per share)	0.00	0.00
Under option, end of year, Weighted-Average Exercise Price (in dollars per share)	0.00	14.76	$ 14.76
Exercisable at end of year, Weighted-Average Exercise Price (in dollars per share)	$ 0.00	$ 14.76
Stock Option Activity, Additional Disclosures
Under option, end of year, Weighted Average Contractual Term	0 years	1 month 20 days
Exercisable at end of year, Weighted Average Contractual Term	0 years	1 month 20 days
Exercised, Aggregate Intrinsic Value	$ 653	$ 167
Under option, end of year, Aggregate Intrinsic Value	0	1,519
Exercisable at end of year, Aggregate Intrinsic Value	$ 0	$ 1,519
Performance-Based
Stock Option Activity, Shares
Under option, beginning of year (in shares)	37,013	142,910
Granted (in shares)	0	0
Exercised (in shares)	(29,014)	(102,309)
Forfeited (in shares)	(288)	(3,588)
Under option, end of year (in shares)	7,711	37,013	142,910
Exercisable at end of year (in shares)	7,711	37,013
Stock Options Weighted Average Exercise Price
Under option, beginning of year, Weighted-Average Exercise Price (in dollars per share)	$ 7.36	$ 15.06
Granted, Weighted-Average Exercise Price (in dollars per share)	0.00	0.00
Exercised, Weighted-Average Exercise Price (in dollars per share)	7.47	17.62
Forfeited, Weighted-Average Exercise Price (in dollars per share)	7.47	21.35
Under option, end of year, Weighted-Average Exercise Price (in dollars per share)	6.94	7.36	$ 15.06
Exercisable at end of year, Weighted-Average Exercise Price (in dollars per share)	$ 6.94	$ 7.36
Stock Option Activity, Additional Disclosures
Under option, end of year, Weighted Average Contractual Term	1 month 9 days	1 year 25 days
Exercisable at end of year, Weighted Average Contractual Term	1 month 9 days	1 year 25 days
Exercised, Aggregate Intrinsic Value	$ 217	$ 1,803
Forfeited, Aggregate Intrinsic Value	2
Under option, end of year, Aggregate Intrinsic Value	308	1,463
Exercisable at end of year, Aggregate Intrinsic Value	$ 308	$ 1,463