Debt - Interest Expense (Details) - Senior Notes - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
2024 Convertible Notes
Schedule of Contractual Maturities
Contractual interest expense	$ 1,033	$ 1,033	$ 3,099	$ 3,100
Amortization of deferred financing costs	156	112	465	335
Amortization of debt discount	0	1,490	0	4,381
Total interest expense	1,189	2,635	3,564	7,816
2025 Convertible Notes
Schedule of Contractual Maturities
Contractual interest expense	1,025	1,024	3,073	3,073
Amortization of deferred financing costs	197	139	586	420
Amortization of debt discount	0	1,747	0	5,138
Total interest expense	$ 1,222	$ 2,910	$ 3,659	$ 8,631