STOCK BASED COMPENSATION - Summary of Assumptions (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Principal assumptions used in applying the Black-Scholes option pricing model for the awards
Risk-free interest rate (as a percent)			1.10%
Volatility factor of the expected market price of common stock (as a percent)	74.00%		70.00%
Weighted-average expected life of option	5 years	5 years	3 years 6 months
Weighted-average grant date fair value (in dollars per share)	$ 2.36	$ 0.49	$ 1.45
Risk-free interest rate, low end of range (as a percent)	1.13%	1.10%
Risk-free interest rate, high end of range (as a percent)	1.21%	1.79%
Additional disclosures
Stock option expense	$ 1,000	$ 1,300	$ 1,300
Fair value of awards vesting in the period	1,300	1,500	2,000
Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount	0	0	0
Unrecognized compensation expense on non-vested stock options (in dollars)	$ 1,400	$ 1,600	$ 1,800
Non-vested stock options outstanding (in shares)	2.5	4.2	2.7
Weighted-average period of recognition	1 year 7 months 6 days	1 year 7 months 6 days	1 year 7 months 6 days
Minimum
Principal assumptions used in applying the Black-Scholes option pricing model for the awards
Dividend yield (as a percent)	0.24%	0.00%
Volatility factor of the expected market price of common stock, low end of range (as a percent)		73.00%
Maximum
Principal assumptions used in applying the Black-Scholes option pricing model for the awards
Dividend yield (as a percent)	0.27%	1.15%
Volatility factor of the expected market price of common stock, high end of range (as a percent)		74.00%