Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Payables and Accruals [Abstract]
Salaries, wages and other benefits	$ 45,716	$ 67,766
Obligation under operating leases	12,890	12,767
Obligation under finance leases	11,611	11,362
Third party commissions	8,490	9,270
Insurance liabilities	3,773	3,954
Fair value of liability derivatives	3,756	4,716
Taxes, other than income	3,425	5,316
Provisions for litigation	2,071	2,580
Severance payments	1,121	970
Earn-outs related to acquisitions	295	295
Other	27,520	24,393
Accrued expenses and other liabilities	$ 120,668	$ 143,389
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent