Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income	$ 2,883	$ 2,880	$ 2,567	$ 1,814	$ 1,363	$ 2,124	$ 2,076	$ 1,551	$ 10,145	$ 7,114
Denominator:
Denominator for basic net income per share - weighted-average outstanding shares (in shares)									12,549	12,282
Effect of dilutive securities:
Stock options and restricted stock (in shares)									1,048	823
Denominator for diluted net income per share - weighted-average outstanding shares (in shares)									13,597	13,105
Net income per share - basic (in dollars per share)	$ 0.23	$ 0.23	$ 0.20	$ 0.15	$ 0.11	$ 0.17	$ 0.17	$ 0.13	$ 0.81	$ 0.58
Net income per share - diluted (in dollars per share)	$ 0.21	$ 0.21	$ 0.19	$ 0.13	$ 0.10	$ 0.16	$ 0.16	$ 0.12	$ 0.75	$ 0.54