EARNINGS PER SHARE (Details) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Income (loss) from continuing operations:
Income (loss) from continuing operations									$ (745,547)	$ 16,982	$ 69,582
Less: undistributed income (loss) to unvested restricted stock									0	315	1,673
Undistributed income (loss) to common shareholders									$ (745,547)	$ 16,667	$ 67,909
Basic income (loss) per common share from continuing operations (in dollars per share) | $ / shares									$ (15.57)	$ 0.42	$ 1.73
Diluted income (loss) per common share from continuing operations (in dollars per share) | $ / shares									$ (15.57)	$ 0.41	$ 1.72
Income (loss) from discontinued operations:
Gain (loss) from discontinued operations									$ 0	$ 3,301	$ (398)
Less: undistributed income to unvested restricted stock									0	62	(10)
Undistributed income (loss) to common shareholders									$ 0	$ 3,239	$ (388)
Basic income per common share from discontinued operations (in dollars per share) | $ / shares									$ 0.00	$ 0.08	$ (0.01)
Diluted income from discontinued operations (in dollars per share) | $ / shares									$ 0.00	$ 0.08	$ (0.01)
Net income (loss):
Net income (loss)	$ (573,663)	$ (112,299)	$ (41,164)	$ (18,421)	$ (43,188)	$ 48,782	$ 1,158	$ 13,531	$ (745,547)	$ 20,283	$ 69,184
Less: undistributed income (loss) to unvested restricted stock									0	377	1,663
Undistributed income (loss) to common shareholders									$ (745,547)	$ 19,906	$ 67,521
Basic net income (loss) per common share (in dollars per share) | $ / shares	$ (12.08)	$ (2.25)	$ (0.83)	$ (0.41)	$ (1.05)	$ 1.18	$ 0.03	$ 0.34	$ (15.57)	$ 0.50	$ 1.72
Diluted net income (loss) per common share (in dollars per share) | $ / shares	$ (12.08)	$ (2.25)	$ (0.83)	$ (0.41)	$ (1.06)	$ 1.18	$ 0.03	$ 0.34	$ (15.57)	$ 0.49	$ 1.71
Weighted-average shares outstanding - basic | shares									47,874,000	40,139,000	39,337,000
Add: dilutive effect of contingent PSUs | shares									0	151,000	66,000
Weighted-average shares outstanding - diluted | shares									47,874,000	40,290,000	39,403,000
Antidilutive securities excluded from EPS calculation | shares									277,634	0	0
PSUs
EARNINGS PER SHARE
Percentage of awards earned during performance cycle									1.33
PSUs | Minimum
EARNINGS PER SHARE
Percentage of awards earned during performance cycle									0
PSUs | Maximum
EARNINGS PER SHARE
Percentage of awards earned during performance cycle									2