Supplemental Financial Information Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	$ 595.7	$ 643.1	$ 1,831.6	$ 1,778.2
Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	595.7	643.1	1,831.6	1,778.2
BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	144.5	151.4	462.7	380.5
UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	99.4	105.3	297.9	273.1
AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	65.9	88.9	229.1	195.8
Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	116.6	132.8	370.6	513.8
ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	88.0	68.7	198.1	141.3
Gulf of America \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	81.3	96.0	273.2	273.7
Floaters \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	302.9	389.0	994.7	1,097.3
Floaters \| BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	144.5	151.4	462.7	380.5
Floaters \| UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Floaters \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	40.0	42.4	117.6	128.4
Floaters \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	4.5	60.5	84.9	268.2
Floaters \| ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	65.0	68.7	149.5	141.3
Floaters \| Gulf of America \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	48.9	66.0	180.0	178.9
Jackups \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	237.1	213.7	688.7	551.8
Jackups \| BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Jackups \| UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	99.4	105.3	297.9	273.1
Jackups \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	25.9	46.5	111.5	67.4
Jackups \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	88.8	61.7	230.7	201.0
Jackups \| ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	23.0	0.0	48.6	0.0
Jackups \| Gulf of America \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.2	0.0	10.3
Other \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	55.7	40.4	148.2	129.1
Other \| BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Other \| UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Other \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Other \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	23.3	10.6	55.0	44.6
Other \| ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.0	0.0	0.0	0.0
Other \| Gulf of America \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	$ 32.4	$ 29.8	$ 93.2	$ 84.5