Consolidated Statements of Equity - USD ($) $ in Thousands	Series A Preferred Stock Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Retained Earnings	Total
Balance at Dec. 31, 2015		$ 73	$ 1,483,105	$ (21)	$ (377,191)	$ 1,105,966
Increase (Decrease) in Shareholders' Equity
Net loss					(192,652)	(192,652)
Other comprehensive income				311		311
Issuance of 61,244 shares of nonvested stock		1	(1)
Nonvested stock amortization			14,512			14,512
Balance at Sep. 30, 2016		74	1,497,616	$ 290	(569,843)	928,137
Balance at Dec. 31, 2016	$ 120,789	74	1,503,784		(594,948)	1,029,699
Increase (Decrease) in Shareholders' Equity
Net loss					(61,295)	(61,295)
Conversion of 27,061,856 shares of Series A Preferred Stock	$ (120,789)	270	120,519
Nonvested stock amortization			3,536			3,536
Balance at Sep. 30, 2017		$ 344	$ 1,627,839		$ (656,243)	$ 971,940