Net Income per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share, Basic [Abstract]
Net income	$ 176,691	$ 132,217	$ 142,943
Average common shares outstanding (in shares)	31,936	32,334	34,179
Basic net income per common share (in dollars per share)	$ 5.53	$ 4.09	$ 4.18
Earnings Per Share, Diluted [Abstract]
Net income	$ 176,691	$ 132,217	$ 142,943
Average common shares outstanding (in shares)	31,936	32,334	34,179
Adjustment for common share equivalents (in shares)	67	28	32
Average common shares outstanding-diluted (in shares)	32,003	32,362	34,211
Diluted net income per common share (in dollars per share)	$ 5.52	$ 4.09	$ 4.18
Anti-dilutive shares (in shares)	3	26	2