Earnings Per Share - Earning per share basic and diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net earnings	$ 1,325	$ 1,162
Denominator:
Basic weighted average shares outstanding (in shares)	9,680	9,781
Effect of dilutive securities:
Employee share-based awards (in shares)	6	5
Diluted weighted average shares outstanding (in shares)	9,686	9,786
Basic earnings per share (in dollars per share)	$ 0.14	$ 0.12
Diluted earnings per share (in dollars per share)	$ 0.14	$ 0.12