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Property, Plant, and Equipment Narrative (Details) $ in Millions	1 Months Ended				3 Months Ended					6 Months Ended			12 Months Ended
	Jun. 30, 2026 USD ($)	Apr. 30, 2026 USD ($)	Jan. 31, 2026 USD ($)	Apr. 30, 2025 USD ($)	Sep. 30, 2026 USD ($)	Jun. 30, 2026 USD ($)	Mar. 31, 2026 USD ($)	Jun. 30, 2025 USD ($) drillship	Mar. 31, 2025 USD ($)	Jun. 30, 2026 USD ($)	Jun. 30, 2025 USD ($) drillship	Mar. 31, 2025 USD ($)	Dec. 31, 2027 USD ($)	Dec. 31, 2025 USD ($)
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets										$ 60.3	$ 27.6
Semisubmersible Rigs, Retired \| drillship								3			3
Other operating (income) loss						$ 0.0	$ 2.8	$ 0.0		2.8	$ (7.8)
Assets held for sale	$ 2.0					2.0				2.0				$ 6.4
Gain (Loss) on Disposition of Property Plant Equipment						37.7		0.8		$ 36.1	$ 27.9
Angola office
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets								2.7	$ 2.5			$ 5.2
Gain (Loss) on Disposition of Property Plant Equipment								4.0
V75 \| Jackups Member
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets			$ 5.0					14.0
Gain (Loss) on Disposition of Property Plant Equipment								23.0
V75 \| Jackups Member \| Subsequent Event
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets													$ 5.0
DPS-3, DPS-5 & DPS-6 \| Floaters
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets				$ 10.0
Asset, Impairment Loss								$ 7.8
DPS-1
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets						10.1
DPS-1 \| Floaters
Property, Plant, and Equipment [Line Items]
Asset, Impairment Loss														15.8
Assets held for sale														$ 6.4
V109 \| Jackups Member
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets	$ 3.4
V109 \| Jackups Member \| Subsequent Event
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets					$ 34.0
Gain (Loss) on Disposition of Property Plant Equipment					$ 31.0
V104 \| Jackups Member
Property, Plant, and Equipment [Line Items]
Proceeds from disposition of assets		$ 40.0
Gain (Loss) on Disposition of Property Plant Equipment						$ 36.6