Segment and Geographic Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Cash and cash equivalents, restricted cash, and marketable securities	$ 3,025,685	$ 244,012
Deferred tax asset	1,816	10,043
Other assets	16,762	11,237
Assets held for sale		495,213
Assets	4,159,046	1,819,512
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 1,114,783	$ 1,059,007