Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Computation of basic and diluted earnings per share
Net income (loss)	$ 7,927	$ (53,817)	$ 16,046	$ (47,843)
Weighted average shares outstanding, basic	52,917,288	46,802,915	52,861,826	45,058,057
Weighted average common equivalent shares	546,289		513,032
Weighted average shares outstanding, diluted	53,463,577	46,802,915	53,374,858	45,058,057
Net earnings (loss) per share
Basic (in dollars per share)	$ 0.15	$ (1.15)	$ 0.30	$ (1.06)
Diluted (in dollars per share)	$ 0.15	$ (1.15)	$ 0.30	$ (1.06)
Restricted stock
Equity instruments excluded from diluted net earnings (loss) per share calculation as the effect would have been anti-dilutive:
Antidilutive shares excluded from computation of diluted earnings per share		159,673		159,673