Stock-Based Compensation and Equity Grants - Schedule of Unrecognized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	$ 4,876	$ 7,385
DLH employees
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	$ 4,567	7,026
Weighted average share based compensation expense recognition period	2 years 5 months 1 day
Non-employee directors
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	$ 309	$ 359