BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Financial Information of Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Revenues	$ 550,233	$ 332,213	$ 1,427,612	$ 874,761
Segment operating income (loss)	33,722	(77,367)	(31,506)	(331,513)
North America Solutions
Segment Reporting Information [Line Items]
Revenues	486,004	281,132	1,235,852	733,061
Offshore Gulf of Mexico
Segment Reporting Information [Line Items]
Revenues	32,701	33,364	91,162	94,911
International Solutions
Segment Reporting Information [Line Items]
Revenues	29,118	15,278	93,699	40,609
Other
Segment Reporting Information [Line Items]
Revenues	2,410	2,439	6,899	6,180
Intersegment
Segment Reporting Information [Line Items]
Revenues	(14,725)	(9,379)	(41,577)	(25,181)
Segment operating income (loss)	(2,140)	(3,298)	(5,453)	(8,857)
Intersegment | North America Solutions
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Intersegment | Offshore Gulf of Mexico
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Intersegment | International Solutions
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Intersegment | Other
Segment Reporting Information [Line Items]
Revenues	(14,725)	(9,379)	(41,577)	(25,181)
Operating Segment
Segment Reporting Information [Line Items]
Revenues	550,233	332,213	1,427,612	874,761
Segment operating income (loss)	56,500	(49,542)	50,632	(240,919)
Operating Segment | North America Solutions
Segment Reporting Information [Line Items]
Revenues	486,004	281,132	1,235,852	733,061
Segment operating income (loss)	57,353	(43,743)	29,757	(226,505)
Operating Segment | Offshore Gulf of Mexico
Segment Reporting Information [Line Items]
Revenues	32,701	33,364	91,162	94,911
Segment operating income (loss)	5,872	5,707	16,616	11,427
Operating Segment | International Solutions
Segment Reporting Information [Line Items]
Revenues	29,118	15,278	93,699	40,609
Segment operating income (loss)	(6,550)	(3,538)	651	(15,353)
Operating Segment | Other
Segment Reporting Information [Line Items]
Revenues	17,135	11,818	48,476	31,361
Segment operating income (loss)	$ 1,965	$ (4,670)	$ 9,061	$ (1,631)