Earnings per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 32,603	$ 838
Net income allocated to unvested restricted stock awards	(37)	0
Net income allocated to common shares	$ 32,566	$ 838
Weighted average shares outstanding	29,329	29,286
Average unvested restricted stock awards	(32)	(68)
Denominator for basic earnings per share—weighted-average shares outstanding	29,297	29,218
Effect of dilutive securities—employee stock options and restricted stock units	135	65
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	29,432	29,283
Basic earnings per share	$ 1.11	$ 0.03
Diluted earnings per share	$ 1.11	$ 0.03
Average antidilutive options and restricted stock units excluded from computation of diluted earnings per share	315	329