Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Net Income per Share
Net income	$ 9,942	$ 9,451	$ 9,108	$ 9,459	$ 8,418	$ 8,496	$ 28,501	$ 26,373
Weighted average common shares outstanding - Basic	10,522			10,372			10,491	10,412
Plus: Potential dilutive common stock equivalents (in shares)	192			135			203	134
Weighted average common shares outstanding - Diluted (in shares)	10,714			10,507			10,694	10,546
Net income per common share - Basic	$ 0.94			$ 0.91			$ 2.72	$ 2.53
Net income per common share - Diluted	$ 0.93			$ 0.90			$ 2.67	$ 2.50
Stock options and common stock excluded from the income per share calculation as their effect would have been anti-dilutive (in shares)				270				234