Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income	$ 2,983	$ 3,481	$ 7,421	$ 2,775	$ 6,538	$ 5,089	$ 958	$ (2,695)	$ 16,660	$ 9,890	$ (7,152)
Denominator:
Weighted average basic shares (in shares)									11,624	11,571	11,507
Dilutive effect of restricted stock units (in shares)									69	63	0
Weighted average diluted shares with assumed conversions (in shares)									11,693	11,634	11,507
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.26	$ 0.30	$ 0.64	$ 0.24	$ 0.56	$ 0.44	$ 0.08	$ (0.23)	$ 1.43	$ 0.85	$ (0.62)
Diluted (in dollars per share)	$ 0.25	$ 0.30	$ 0.64	$ 0.24	$ 0.56	$ 0.44	$ 0.08	$ (0.23)	$ 1.42	$ 0.85	$ (0.62)