RECONCILIATION OF EARNINGS PER SHARE - Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income (Loss)	$ (54,470)	$ 53,314	$ 36,759	$ (203,116)	$ (590,806)	$ (227,904)	$ (111,601)	$ (15,420)	$ (167,513)	$ (945,731)	$ 568,032
Basic Shares Outstanding (in shares)									94,475,797	76,078,371	72,896,579
Basic earnings per average common share (in dollars per share)	$ (0.56)	$ 0.55	$ 0.38	$ (2.34)	$ (7.50)	$ (2.89)	$ (1.52)	$ (0.21)	$ (1.77)	$ (12.43)	$ 7.79
Effect of dilutive securities
Net Income (Loss), Diluted EPS	$ (54,470)	$ 53,314	$ 36,759	$ (203,116)	$ (590,806)	$ (227,904)	$ (111,601)	$ (15,420)	$ (167,513)	$ (945,731)	$ 568,032
Diluted Shares Outstanding (in shares)									94,475,797	76,078,371	73,274,631
Diluted earnings per average common share (in dollars per share)	$ (0.56)	$ 0.55	$ 0.38	$ (2.34)	$ (7.50)	$ (2.89)	$ (1.52)	$ (0.21)	$ (1.77)	$ (12.43)	$ 7.75
Stock options
Effect of dilutive securities
Effect of dilutive securities (in shares)									0	0	216,000
Non-vested restricted stock
Effect of dilutive securities
Effect of dilutive securities (in shares)									0	0	58,000
Performance share awards
Effect of dilutive securities
Effect of dilutive securities (in shares)									0	0	104,000