STOCK-BASED COMPENSATION - Schedule of Awards Outstanding and Exercisable (Details) - Stock Options and Stock Appreciation Rights (SARs) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise prices (dollars per share)	$ 6.56	$ 6.64
Grants outstanding (shares)	226
Grants exercisable (shares)	206
$8.14 to $10.80
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (dollars per share)	$ 8.14
Range of exercise prices, maximum (dollars per share)	10.80
Weighted average exercise prices (dollars per share)	$ 9.32
Grants outstanding (shares)	60
Intrinsic value - grants outstanding	$ 0
Grants exercisable (shares)	40
Intrinsic value - grants exercisable	$ 0
$2.37 to $6.21
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise prices, minimum (dollars per share)	$ 2.37
Range of exercise prices, maximum (dollars per share)	6.21
Weighted average exercise prices (dollars per share)	$ 5.56
Grants outstanding (shares)	166
Intrinsic value - grants outstanding	$ 206
Grants exercisable (shares)	166
Intrinsic value - grants exercisable	$ 206