BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Reconciliation of Segment Assets to Consolidated Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Assets	$ 4,340,816	$ 4,355,531
Operating Segments
Segment Reporting Information [Line Items]
Assets	4,024,154	3,939,096
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets	316,662	416,435
North America Solutions | Operating Segments
Segment Reporting Information [Line Items]
Assets	3,381,446	3,406,824
Offshore Gulf of Mexico | Operating Segments
Segment Reporting Information [Line Items]
Assets	77,539	80,993
International Solutions | Operating Segments
Segment Reporting Information [Line Items]
Assets	406,471	330,974
Other | Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 158,698	$ 120,305