Supplemental Financial Information Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	$ 610.1	$ 415.2	$ 1,135.1	$ 845.3
Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	610.1	415.2	1,135.1	845.3
BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	98.0	33.9	229.1	71.0
UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	95.6	68.1	167.8	121.6
US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	83.0	77.3	177.7	153.3
AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	59.2	50.7	106.9	101.3
ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	42.1	58.2	72.6	97.3
Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	232.2	127.0	381.0	300.8
Floaters \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	383.9	227.4	708.3	442.2
Floaters \| BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	98.0	33.9	229.1	71.0
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 \| US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	56.1	45.3	112.9	87.0
Floaters \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	43.0	40.1	86.0	77.8
Floaters \| ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	42.1	58.2	72.6	97.3
Floaters \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	144.7	49.9	207.7	109.1
Jackups \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	185.8	144.6	338.1	314.4
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	95.6	68.1	167.8	121.6
Jackups \| US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.7	5.8	10.1	14.0
Jackups \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	16.2	10.6	20.9	23.5
Jackups \| 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
Jackups \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	73.3	60.1	139.3	155.3
Other \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	40.4	43.2	88.7	88.7
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 \| US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	26.2	26.2	54.7	52.3
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 \| 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 \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	$ 14.2	$ 17.0	$ 34.0	$ 36.4