BUSINESS SEGMENTS AND GEOGRAPHIC INFORMATION - Financial Information of Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 467,597	$ 296,171	$ 877,379	$ 542,548
Segment operating income (loss)	(22,617)	(160,923)	(65,228)	(254,146)
North America Solutions
Segment Reporting Information [Line Items]
Revenues	408,814	249,939	749,848	451,929
Offshore Gulf of Mexico
Segment Reporting Information [Line Items]
Revenues	29,147	29,274	58,461	61,547
International Solutions
Segment Reporting Information [Line Items]
Revenues	27,422	14,813	64,581	25,331
Other
Segment Reporting Information [Line Items]
Revenues	2,214	2,145	4,489	3,741
Intersegment
Segment Reporting Information [Line Items]
Revenues	(13,204)	(8,680)	(26,852)	(15,802)
Segment operating income (loss)	(2,031)	(3,433)	(3,313)	(5,559)
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	(13,204)	(8,680)	(26,852)	(15,802)
Operating Segment
Segment Reporting Information [Line Items]
Revenues	467,597	296,171	877,379	542,548
Segment operating income (loss)	6,863	(114,819)	(5,868)	(191,377)
Operating Segment | North America Solutions
Segment Reporting Information [Line Items]
Revenues	408,814	249,939	749,848	451,929
Segment operating income (loss)	1,297	(109,834)	(27,596)	(182,762)
Operating Segment | Offshore Gulf of Mexico
Segment Reporting Information [Line Items]
Revenues	29,147	29,274	58,461	61,547
Segment operating income (loss)	5,278	2,978	10,744	5,720
Operating Segment | International Solutions
Segment Reporting Information [Line Items]
Revenues	27,422	14,813	64,581	25,331
Segment operating income (loss)	(848)	(3,458)	7,201	(11,815)
Operating Segment | Other
Segment Reporting Information [Line Items]
Revenues	15,418	10,825	31,341	19,543
Segment operating income (loss)	$ 3,167	$ (1,072)	$ 7,096	$ 3,039