Income Taxes (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	Sep. 30, 2017
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 1,050				$ 1,075				$ 1,050	$ 1,075	$ 0	$ 0
Income Tax Examination, Penalties and Interest Accrued	(143)				(95)				$ (143)	$ (95)	$ 0
Federal statutory income tax rate, percent									21.00%	21.00%	35.00%
Blended U.S. Federal Statutory Rate											24.50%
Income tax expense	(4,035)	$ (740)	$ 7	$ (2,603)	(10,721)	$ (7,959)	$ 4,579	$ 4,514	$ (7,371)	$ (9,587)	$ (1,382)
Undistributed earnings of foreign subsidiaries	53,766				49,480				53,766	49,480	36,879
Net operating loss carryforwards	29,407				49,786				29,407	49,786
Tax cuts and jobs act of 2017, change in tax rate, deferred tax liability, income tax (expense) benefit										3,641
Tax cuts and jobs act 2017, Impact on deferred tax asset, net of valuation allowance										0
Domestic Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	105,828								105,828
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Operating loss carryforwards	66,206								66,206
Foreign Tax Authority
Income Tax Contingency [Line Items]
Operating loss carryforwards	1,770								1,770
Foreign Tax Authority with Indefinite Expiration
Income Tax Contingency [Line Items]
Operating loss carryforwards	18,467								18,467
Other Current Liabilities [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 1,288				$ 1,170				$ 1,288	$ 1,170	$ 0