Segment and Geographic Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Segment Reporting Information [Line Items]
Cash and cash equivalents, restricted cash, and marketable securities	$ 231,817	$ 244,012
Deferred tax asset	13,845	10,043
Other assets	15,019	11,237
Assets held for sale	510,695	495,213
Assets	1,854,937	1,819,512
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 1,083,561	$ 1,059,007