Stockholders' Equity - Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Equity [Abstract]
Net income	$ 9,853	$ 628
Weighted average number of common shares outstanding (in shares)	30,219	29,872
Dilutive effect of restricted stock grants after application of the treasury stock method (in shares)	355	322
Dilutive shares outstanding (in shares)	30,574	30,194
Basic earnings per share (in dollars per share)	$ 0.33	$ 0.02
Diluted earnings per share (in dollars per share)	$ 0.32	$ 0.02