Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Components of Accrued liabilities
Accrued employee compensation and benefits	$ 5,476	$ 4,238
Accrued workers’ compensation	546	181
Contract liabilities	636	382	$ 0
Other accrued liabilities	1,632	756
Total accrued liabilities	$ 8,290	$ 5,557