BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Reconciliation of Segment Assets to Consolidated Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Segment Reporting Information [Line Items]
Assets	$ 4,421,328	$ 4,381,956
Operating Segments
Segment Reporting Information [Line Items]
Assets	4,012,221	3,954,955
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Assets	409,107	427,001
North America Solutions | Operating Segments
Segment Reporting Information [Line Items]
Assets	3,347,139	3,320,203
Offshore Gulf of Mexico | Operating Segments
Segment Reporting Information [Line Items]
Assets	76,294	73,319
International Solutions | Operating Segments
Segment Reporting Information [Line Items]
Assets	440,094	407,143
Other | Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 148,694	$ 154,290