Net Income per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income	$ 27,296	$ 20,009	$ 114,372	$ 133,952
Less distributed and undistributed earnings allocated to participating securities	39	104	219	792
Net Income (Loss) Available to Common Stockholders, Basic	$ 27,257	$ 19,905	$ 114,153	$ 133,160
Weighted average common shares outstanding basic (in shares)	38,524	38,507	38,445	38,625
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	357	234	404	193
Weighted Average Number of Shares Outstanding, Diluted	38,881	38,741	38,849	38,818