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	Sep. 30, 2019
Numerator:
Net income	$ 3,261	$ (2,041)	$ (225)	$ (364)	$ 2,983	$ 3,481	$ 7,421	$ 2,775	$ 631	$ 16,660	$ 9,890
Denominator:
Weighted average basic shares (in shares)									11,705	11,624	11,571
Dilutive effect of restricted stock units (in shares)									84	69	63
Weighted average diluted shares (in shares)									11,789	11,693	11,634
Earnings per share:
Basic (in dollars per share)	$ 0.28	$ (0.17)	$ (0.02)	$ (0.03)	$ 0.26	$ 0.30	$ 0.64	$ 0.24	$ 0.05	$ 1.43	$ 0.85
Diluted (in dollars per share)	$ 0.28	$ (0.17)	$ (0.02)	$ (0.03)	$ 0.25	$ 0.30	$ 0.64	$ 0.24	$ 0.05	$ 1.42	$ 0.85