Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss)	$ (2,041)	$ (225)	$ (364)	$ 3,481	$ 7,421	$ 2,775	$ (2,629)	$ 13,677
Denominator:
Weighted average basic shares (in shares)	11,720			11,631			11,700	11,622
Dilutive effect of restricted stock units (in shares)	0			67			0	64
Weighted average diluted shares (in shares)	11,720			11,698			11,700	11,686
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.17)			$ 0.30			$ (0.22)	$ 1.18
Diluted (in dollars per share)	$ (0.17)			$ 0.30			$ (0.22)	$ 1.17