Revenue from Contracts with Customers - Revenue By Geographic Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	$ 518,639	$ 542,342	$ 1,671,925	$ 1,550,433
Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	518,639	542,342	1,671,925	1,550,433
Americas | Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	253,592	278,329	781,480	761,617
Europe | Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	170,617	173,559	624,884	549,835
Asia-Pacific | Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	$ 94,430	$ 90,454	$ 265,561	$ 238,981