PROPERTY, PLANT AND EQUIPMENT - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 30, 2022 rig	Jun. 30, 2023 USD ($) rig	Jun. 30, 2022 USD ($) rig	Jun. 30, 2023 USD ($) rig	Jun. 30, 2022 USD ($) rig	Sep. 30, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Depreciation		$ 93,200	$ 97,500	$ 282,700	$ 293,500
Abandonments included in depreciation		200	1,400	2,400	5,200
Rigs damaged by fire | rig	1
Abandonment expense				9,200
Insurance		7,800
Property, plant and equipment, net		2,932,593		2,932,593		$ 2,960,809
Asset impairment charges		0	0	12,097	4,363
Other gain on sale of assets		4,504	(3,075)	(394)	(2,762)
Assets held-for-sale		988		988		$ 4,333
Gain on reimbursement of drilling equipment		$ (10,642)	$ (9,895)	$ (37,940)	$ (21,597)
International FlexRig
Property, Plant and Equipment [Line Items]
Number of rigs, held-for -sale | rig		4		4
Property, plant and equipment, net		$ 8,800		$ 8,800
Property, plant, and equipment, salvage value		$ 700		700
Asset impairment charges				$ 8,100
International FlexRig | International Solutions
Property, Plant and Equipment [Line Items]
Number of rigs, held-for -sale | rig			2		2
Property, plant and equipment, net			$ 3,400		$ 3,400
Asset impairment charges					2,500
Proceeds from sale of assets					900
Assets held-for-sale			$ 900		900
Conventional Drilling Rigs
Property, Plant and Equipment [Line Items]
Number of rigs, held-for -sale | rig		4		4
Assets Previously Held For Sale
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net		$ 3,000		$ 3,000
Property, plant, and equipment, salvage value		300		300
Asset impairment charges				2,700
Additional Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net		1,400		1,400
Property, plant, and equipment, salvage value		$ 100		100
Asset impairment charges				1,300
Assets Related To Trucking And Casino Running Services | North America Solutions
Property, Plant and Equipment [Line Items]
Proceeds from sale of assets					6,000
Other gain on sale of assets					3,400
Earnout proceeds from sale				$ 1,400	$ 900
Partial Rig Substructures | North America Solutions
Property, Plant and Equipment [Line Items]
Number of rigs, held-for -sale | rig			2		2
Property, plant and equipment, net			$ 2,000		$ 2,000
Property, plant, and equipment, salvage value			$ 100		100
Asset impairment charges					$ 1,900
FlexRig4 Asset Group | United Arab Emirates
Property, Plant and Equipment [Line Items]
Number of rigs, held-for -sale | rig			5		5
Property, plant and equipment, net			$ 34,500		$ 34,500
Other gain on sale of assets					(1,100)
Sale of property, plant and equipment, selling costs					$ 15,700