Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income	$ 2,076	$ 1,265	$ 3,628	$ 2,955
Denominator:
Denominator for basic net income (loss) per share - weighted-average outstanding shares (in shares)	12,299	12,036	12,193	11,999
Effect of dilutive securities:
Stock options and restricted stock (shares)	704	1,051	693	1,031
Denominator for diluted net income (loss) per share - weighted-average outstanding shares (in shares)	13,003	13,087	12,886	13,030
Net income per share - basic (in dollars per share)	$ 0.17	$ 0.11	$ 0.30	$ 0.25
Net income per share - diluted (in dollars per share)	$ 0.16	$ 0.10	$ 0.28	$ 0.23