Segment and Geographic Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Cash and cash equivalents, restricted cash, and marketable securities	$ 1,296,074	$ 2,305,081
Deferred tax asset	599	1,169
Other assets	623	181,479
Assets	3,069,416	3,716,122
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 1,772,719	$ 1,228,393