Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator [Abstract]
Net income	$ 21,142	$ 17,447	$ 68,691	$ 43,678
Basic earnings per share [Abstract]
Weighted average shares (in shares)	17,790,000	17,746,000	17,783,000	17,746,000
Diluted earnings per share [Abstract]
Effect of dilutive stock options and restricted stock grants (in shares)	18,000	6,000	15,000	7,000
Adjusted weighted average shares (in shares)	17,808,000	17,752,000	17,798,000	17,753,000
Earnings per share [Abstract]
Basic earnings per share (in dollars per share)	$ 1.19	$ 0.98	$ 3.86	$ 2.46
Diluted earnings per share (in dollars per share)	$ 1.19	$ 0.98	$ 3.86	$ 2.46
Options [Member]
Earnings Per Share [Abstract]
Options excluded from diluted calculations (in shares)	0	0	0	0