Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Contingency [Line Items]
Income tax (expense) benefit at the federal statutory rate of 21%	$ (12,966)	$ (25,571)	$ (234)
State and local income taxes, net of federal tax benefit	(757)	(74)	(204)
Foreign tax rate differential	(3,009)	(1,129)	(1,471)
Nondeductible interest expense	(588)	(1,032)	(1,073)
Meals and entertainment expense	(176)	(760)	(953)
U.S. tax on foreign earnings	(5,687)	(8,438)	(1,421)
Nondeductible legal expenses	0	0	(112)
Other nondeductible expenses	(786)	(479)	(223)
Impact of tax rate changes	819	286	(548)
Valuation allowances	854	19,013	(3,886)
Share-based compensation	11,598	4,931	475
Non-taxable gain on sale of subsidiary	0	4,789	0
Return-to-provision adjustments	(44)	516	(655)
Non-controlling interest	30	(466)	221
Net benefit of foreign R&D expenses	0	18	191
Transaction related contingent liabilities	155	143	(58)
Contingent liabilities - warranty	0	0	93
Foreign withholding taxes	0	0	369
Non-deductible exchange gain or loss	0	0	(587)
Deferred tax adjustments	87	491	2,016
Accrued tax adjustments	27	(6)	(1,348)
Tax benefits of other comprehensive income	0	0	(154)
Other	363	397	(25)
Income taxes	$ (10,080)	$ (7,371)	$ (9,587)