Net (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income (loss)	$ 27,396	$ 23,917	$ 21,390	$ 31,643	$ 26,981	$ 23,587	$ 12,713	$ 17,073	$ 104,346	$ 80,354	$ (342,750)
Less: Net (income) loss allocated to unvested participating restricted stock									(3,532)	(2,711)	6,768
Net income (loss) available to common stockholders									100,814	77,643	(335,982)
Effect of unvested participating restricted stock									33	16	0
Numerator - net income (loss) available to common shareholders - diluted									$ 100,847	$ 77,659	$ (335,982)
Weighted average outstanding shares of common stock - basic (in shares)									16,934	17,533	17,725
Stock options (in shares)									311	256	15
Weighted average outstanding shares of common stock - diluted (in shares)									17,245	17,789	17,740
Basic (in dollars per share)	$ 1.61	$ 1.38	$ 1.20	$ 1.76	$ 1.49	$ 1.31	$ 0.70	$ 0.93	$ 5.95	$ 4.43	$ (18.96)
Diluted (in dollars per share)	$ 1.59	$ 1.36	$ 1.18	$ 1.73	$ 1.47	$ 1.29	$ 0.69	$ 0.92	$ 5.85	$ 4.37	$ (18.96)