Income Taxes Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Current:
Federal	$ 0	$ 0	$ 0
State	(1,233)	(591)	(400)
Foreign	(11,210)	(8,014)	(7,239)
Current income tax provision	(12,443)	(8,605)	(7,639)
Deferred:
Federal	(2,153)	115	(3,597)
State	(630)	401	196
Foreign	5,146	718	1,453
Deferred income tax provision	2,363	1,234	(1,948)
Income taxes	$ (10,080)	$ (7,371)	$ (9,587)