Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Tax Contingency [Line Items]
Income tax (expense) benefit at the federal statutory rate of 21%									$ (25,571)	$ (234)	$ (2,270)
State and local income taxes, net of federal tax benefit									(74)	(204)	(1,053)
Foreign tax rate differential									(1,129)	(1,471)	(2,389)
Nondeductible transaction costs									0	0	(1,489)
Nondeductible interest expense									(1,032)	(1,073)	(853)
Meals and entertainment expense									(760)	(953)	(553)
U.S. tax on foreign earnings									(8,438)	(1,421)	0
Nondeductible legal expenses									0	(112)	0
Other nondeductible expenses									(479)	(223)	(47)
Impact of tax rate changes									286	(548)	3,626
Valuation allowances									19,013	(3,886)	(4,218)
Share-based compensation in excess of accounting									4,931	475	5,156
Non-taxable gain on sale of subsidiary									4,789	0	1,131
Return-to-provision adjustments									516	(655)	449
Non-controlling interest									(466)	221	428
Net benefit of foreign R&D expenses									18	191	336
Transaction related contingent liabilities									143	(58)	89
Contingent liabilities - warranty									0	93	0
Foreign withholding taxes									0	369	0
Non-deductible exchange gain or loss									0	(587)	0
Deferred tax adjustments									491	2,016	0
Accrued tax adjustments									(6)	(1,348)	0
Tax benefits of other comprehensive income									0	(154)	0
Other									397	(25)	275
Income taxes	$ (4,035)	$ (740)	$ 7	$ (2,603)	$ (10,721)	$ (7,959)	$ 4,579	$ 4,514	$ (7,371)	$ (9,587)	$ (1,382)