Earnings (Loss) Per Common Share - Computation of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income (loss)	$ (23,149)	$ (173,811)	$ (226,778)
Less:
Net income (loss) attributable to non-controlling interests	(5,137)	(51,071)
Net income (loss) available for common shareholders	$ (18,012)	$ (122,740)
Weighted-average common shares outstanding (in shares)	52,599,000	42,185,000
Earnings (Loss) per Common Share
Basic (in dollars per share)	$ (0.34)	$ (2.91)
Diluted (in dollars per share)	$ (0.34)	$ (2.91)
Class B
Earnings (Loss) per Common Share
Convertible preferred stock, shares issued upon conversion (in shares)	1