Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 5,760	$ 5,171	$ 5,368	$ 5,959	$ 5,834	$ 5,740	$ 16,299	$ 17,533
Weighted average common shares outstanding - Basic (in shares)	10,630			10,863			10,768	10,836
Plus: Potential dilutive common stock equivalents (in shares)	76			173			107	183
Weighted average common shares outstanding - Diluted (in shares)	10,706			11,036			10,875	11,019
Net income per common share - Basic (in dollars per share)	$ 0.54			$ 0.55			$ 1.51	$ 1.62
Net income per common share - Diluted (in dollars per share)	$ 0.54			$ 0.54			$ 1.50	$ 1.59
Stock options and common stock excluded from the income per share calculation as their effect would have been anti-dilutive (in shares)	430			251			413	237