Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Payables and Accruals [Abstract]
Salaries, wages, and other benefits	$ 60,552	$ 79,110
Obligation under operating leases	14,668	13,316
Obligation under finance leases	12,263	12,093
Third party commissions	10,563	10,031
Frontier Purchase Right liability	10,396	0
Taxes, other than income	6,811	4,575
Provision for litigation	6,153	2,938
Insurance liabilities	3,557	3,720
Severance payments	888	304
Fair value of liability derivatives	33	554
Earn-outs related to acquisitions	25	150
Other	32,601	33,576
Accrued expenses and other liabilities	$ 158,510	$ 160,367
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other liabilities