Stock-based Compensation and Equity Grants - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	$ 5,660		$ 5,660
DLH employees
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	5,498		$ 5,498
Weighted average share based compensation expense recognition period			4 years 1 month 24 days
Non-employee directors
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total unrecognized expense	162		$ 162
Non-employee directors | Restricted Stock Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of restricted stock units granted (in shares)			53,510
NEO | Restricted Stock Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of restricted stock units granted (in shares)			161,485
Selling, General and Administrative Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock option expense	643	$ 473	$ 1,952	$ 1,317
Selling, General and Administrative Expenses | DLH employees
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock option expense	481	356	1,466	968
Selling, General and Administrative Expenses | Non-employee directors
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock option expense	$ 162	$ 117	$ 486	$ 349