Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net income	$ 3,481	$ 7,421	$ 2,775	$ 5,089	$ 958	$ (2,695)	$ 13,677	$ 3,352
Denominator:
Weighted average basic shares (in shares)	11,631			11,579			11,622	11,567
Dilutive effect of restricted stock units (in shares)	67			24			64	22
Weighted average diluted shares (in shares)	11,698			11,603			11,686	11,589
Income per share:
Basic (in dollars per share)	$ 0.30			$ 0.44			$ 1.18	$ 0.29
Diluted (in dollars per share)	$ 0.30			$ 0.44			$ 1.17	$ 0.29