STOCK-BASED COMPENSATION - Schedule of Activity of Equity Compensation Plans (Details) - Stock Options and Stock Appreciation Rights (SARs) shares in Thousands	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Number of Shares
Outstanding, beginning (shares) | shares	122
Granted (shares) | shares	0
Exercised (shares) | shares	(2)
Expired or cancelled (shares) | shares	(21)
Outstanding, ending (shares) | shares	99
Exercisable (shares) | shares	89
Weighted Average Exercise Price
Outstanding, beginning (dollars per share) | $ / shares	$ 7.29
Granted (dollars per share) | $ / shares	0.00
Exercised (dollars per share) | $ / shares	2.37
Expired or cancelled (dollars per share) | $ / shares	8.36
Outstanding, ending (dollars per share) | $ / shares	7.16
Exercisable, weighted average exercise price (dollars per share) | $ / shares	$ 7.05