Net Income per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income per Share
Net income	$ 8,496	$ 5,368
Weighted average common shares outstanding - Basic	10,437	10,883
Plus: Potential dilutive common stock equivalents (in shares)	128	154
Weighted average common shares outstanding - Diluted (in shares)	10,565	11,037
Net income per common share - Basic	$ 0.81	$ 0.49
Net income per common share - Diluted	$ 0.80	$ 0.49
Stock options and common stock excluded from the income per share calculation as their effect would have been anti-dilutive (in shares)	154	363