Earnings Per Share & Diluted Earnings Per Share - Reconciliation of Denominators of Basic and Diluted EPS Calculations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net (loss) income		$ (12,582)	$ 17,367	$ 1,508
Denominator:
Weighted-average shares used to compute basic EPS		14,065	14,014	14,189
Weighted-average shares used to compute diluted EPS		14,065	14,184	14,340
Net (loss) income per basic share		$ (0.89)	$ 1.24	$ 0.11
Net (loss) income per diluted share		$ (0.89)	$ 1.22	$ 0.11
Stock Options
Denominator:
Dilutive potential common shares due to stock options	[1]		170	151

[1] The number of common stock equivalents is calculated using the treasury stock method and the average market price during the period.