Supplemental Financial Information Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	$ 643.1	$ 455.1	$ 1,778.2	$ 1,300.4
Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	643.1	455.1	1,778.2	1,300.4
BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	151.4	46.4	380.5	117.4
UNITED KINGDOM \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	105.3	71.0	273.1	192.6
US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	96.0	100.0	273.7	253.3
AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	88.9	47.0	195.8	148.3
ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	68.7	62.8	141.3	160.1
Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	132.8	127.9	513.8	428.7
Floaters \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	389.0	243.3	1,097.3	685.5
Floaters \| BRAZIL \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	151.4	46.4	380.5	117.4
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	66.0	65.3	178.9	152.3
Floaters \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	42.4	40.2	128.4	118.0
Floaters \| ANGOLA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	68.7	62.8	141.3	160.1
Floaters \| Other Geographic Areas \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	60.5	28.6	268.2	137.7
Jackups \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	213.7	165.9	551.8	480.3
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	105.3	71.0	273.1	192.6
Jackups \| US Gulf Of Mexico \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	0.2	8.5	10.3	22.5
Jackups \| AUSTRALIA \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	46.5	6.8	67.4	30.3
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	61.7	79.6	201.0	234.9
Other \| Revenue Benchmark [Member] \| Geographic Concentration Risk
Revenues from External Customers and Long-Lived Assets [Line Items]
OPERATING REVENUES	40.4	45.9	129.1	134.6
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	29.8	26.2	84.5	78.5
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	$ 10.6	$ 19.7	$ 44.6	$ 56.1