EARNINGS (LOSS) PER SHARE - Calculation of Earning Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended	36 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2018	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2019
Numerator for basic and diluted earnings per share
Net loss	$ (11,508)	$ (9,850)	$ (4,306)	$ (10,438)	$ (5,288)	$ (15,726)	$ (20,032)	$ (29,882)	$ (48,600)
Preferred dividends	(334)	0	(334)	0	(334)	(334)	(668)	(668)
Net loss applicable to common shares	$ (11,842)	$ (9,850)	$ (4,640)	$ (10,438)	$ (5,622)	$ (16,060)	$ (20,700)	$ (30,550)
Denominator for basic loss per share - Weighted average shares outstanding (in shares)	60,096,852	60,065,978	60,065,053	60,059,936	60,053,912	60,056,924	60,059,594	60,061,243
Effect of dilutive potential common shares (in shares)	0				0
Denominator for diluted loss per share - Adjusted weighted average shares outstanding (in shares)	60,096,852	60,065,978	60,065,053	60,059,936	60,053,912	60,056,924	60,059,594	60,061,243
Basic loss per share (in dollars per share)	$ (0.20)	$ (0.16)	$ (0.08)	$ (0.17)	$ (0.09)	$ (0.27)	$ (0.34)	$ (0.51)
Diluted loss per share (in dollars per share)	$ (0.20)	$ (0.16)	$ (0.08)	$ (0.17)	$ (0.09)	$ (0.27)	$ (0.34)	$ (0.51)