Net Income (Loss) Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021		Sep. 30, 2020
Numerator:
Net income and comprehensive income from continuing operations	$ 30,503	$ 16,992	$ 77,894		$ 37,634
Net loss and comprehensive loss from discontinued operation	(6,967)	(345)	(12,500)		(9,458)
Net income and comprehensive income	23,536	16,647	65,394		28,176
Income allocated to participating securities	(235)	(150)	(541)		(184)
Numerator for basic and diluted net income per share for continuing operations	$ 30,268	$ 16,842	$ 77,353		$ 37,450
Denominator:
Denominator for basic income per share - weighted-average number of common shares outstanding (in shares)	27,034	27,559	27,217		27,732
Dilutive stock options and performance share awards (in shares)	110	47	134		57
Denominator for diluted income per share - weighted-average number of common shares and share equivalents outstanding (in shares)	27,144	27,606	27,351		27,789
Basic net income (loss) per share
Continuing operations (in dollars per share)	$ 1.12	$ 0.61	$ 2.84		$ 1.35
Discontinued operation (in dollars per share)	(0.26)	(0.01)	(0.46)		(0.34)
Net income per basic share (in dollars per share)	0.86	0.60	2.39	[1]	1.01	[1]
Diluted net income (loss) per share
Continuing operations (in dollars per share)	1.12	0.61	2.83		1.35
Discontinued operation (in dollars per share)	(0.26)	(0.01)	(0.46)		(0.34)
Net income per diluted share (in dollars per share)	$ 0.86	$ 0.60	$ 2.37		$ 1.01

[1] Rounding may impact summation of amounts.