STOCK-BASED COMPENSATION - Stock option and restricted stock option activity (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Option Shares
Treasury Stock, Common, Value	$ 1,211		$ 723
Options [Member]
Option Shares
Outstanding at the beginning of the period (in shares)	757	759
Granted (in shares)	8	157
Options Exercised/RSAs Vested (in shares)	(7)	(58)
Forfeited (in shares)	(3)	(18)
Expired (in shares)	0	(1)
Outstanding at the end of the period (in shares)	755	839
Restricted Stock Awards [Member]
Option Shares
Outstanding at the beginning of the period (in shares)	192	117
Granted (in shares)	0	122
Options Exercised/RSAs Vested (in shares)	(49)	(11)
Forfeited (in shares)	0	(2)
Expired (in shares)	0	0
Outstanding at the end of the period (in shares)	143	226
Share-based Compensation Arrangement , Share-based Payment Award, Number of Shares Re-purchased from Employees	13
Treasury Stock, Common, Value	$ 488