Summary of Significant Accounting Policies - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	$ 36,885	$ 30,425
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	30,425	34,335
Other comprehensive income (loss) before reclassifications	1,408	1,068
Amounts reclassified from accumulated other comprehensive income (loss)	5,642	203
Net current-period other comprehensive income (loss)	7,050	1,271
Ending balance	36,885	30,425
Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	1,661	(5,389)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,389)	(6,660)
Ending balance	1,661	(5,389)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	0	(5,554)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5,554)	(5,928)
Other comprehensive income (loss) before reclassifications	0	374
Amounts reclassified from accumulated other comprehensive income (loss)	5,554	0
Net current-period other comprehensive income (loss)	5,554	374
Ending balance	0	(5,554)
Retirement Plan Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	1,661	163
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	163	(741)
Other comprehensive income (loss) before reclassifications	1,408	701
Amounts reclassified from accumulated other comprehensive income (loss)	90	203
Net current-period other comprehensive income (loss)	1,498	904
Ending balance	1,661	163
Interest Rates Swap Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	0	2
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2	9
Other comprehensive income (loss) before reclassifications	0	(7)
Amounts reclassified from accumulated other comprehensive income (loss)	(2)	0
Net current-period other comprehensive income (loss)	(2)	(7)
Ending balance	$ 0	$ 2