Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Payables and Accruals [Abstract]
Salaries, wages and other benefits	$ 59,245	$ 67,766
Obligation under operating leases	13,119	12,767
Obligation under finance leases	11,869	11,362
Third party commissions	9,192	9,270
Insurance liabilities	3,760	3,954
Fair value of liability derivatives	166	4,716
Taxes, other than income	3,939	5,316
Provisions for litigation	2,072	2,580
Severance payments	1,185	970
Earn-outs related to acquisitions	295	295
Other	28,360	24,393
Accrued expenses and other liabilities	$ 134,692	$ 143,389
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
Option and Purchase Right	$ 1,490	$ 0