Supporting Financial Information - Accounts Payable, Accrued Expense and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts payable	$ 14,198	$ 16,684
Accrued benefits	2,803	2,916
Accrued bonus and incentive compensation	1,200	2,381
Accrued workers' compensation insurance	5,885	7,014
Other accrued expenses	6,297	3,722
Accounts payable, accrued expenses, and other current liabilities	$ 30,383	$ 32,717