Net Income (Loss) per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator for basic and diluted income per common share:
Net income	$ 24,850	$ 25,603
Less: Net income allocated to unvested participating restricted stock	(598)	(548)
Net income available to common stockholders	24,252	25,055
Effect of unvested participating restricted stock in two-class calculation	1	6
Net income available to common stockholders - diluted	$ 24,253	$ 25,061
Denominator:
Weighted average outstanding shares of common stock - basic (in shares)	16,722	16,460
Dilutive effect of stock options (in shares)	36	170
Weighted average outstanding shares of common stock - diluted (in shares)	16,758	16,630
Net income per common share:
Net income per common share - basic (USD per share)	$ 1.45	$ 1.52
Net income per common share - diluted (USD per share)	$ 1.45	$ 1.51