v3.26.3
Segment Information (Schedule Of Segment Reporting Information) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Jun. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) $ 555.6   $ 555.6 $ 1,488.0 $ 1,705.7  
Reimbursable revenues 38.0   40.1 110.2 125.9  
Total operating revenues 593.6   595.7 1,598.2 1,831.6  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses 379.9   367.6 1,100.7 1,096.8  
Reimbursable expenses 37.4   38.0 105.5 119.5  
Total contract drilling expenses (exclusive of depreciation) 417.3   405.6 1,206.2 1,216.3  
Depreciation 47.3   37.1 134.6 105.7  
General and administrative 25.7   26.9 78.2 70.1  
Business Combination, Acquisition-Related Cost, Expense 15.5   0.0 40.5 0.0  
Other Operating Income (Expense), Net 3.0 $ (2.8) 0.0 0.2 7.8  
Costs and Expenses 508.8   469.6 1,459.7 1,399.9  
Equity in earnings of ARO 3.5   (4.4) (13.9) (5.9)  
OPERATING INCOME 81.3   130.5 152.4 437.6  
Property and equipment, net (2,259.2)   (2,034.4) (2,259.2) (2,034.4) $ (2,088.8)
Capital expenditures 121.6   69.8 328.0 237.2  
Operating Segments | Floaters            
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) 346.0   293.0 817.6 968.7  
Reimbursable revenues 13.3   9.9 29.3 26.0  
Total operating revenues 359.3   302.9 846.9 994.7  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses 188.8   187.7 507.3 568.0  
Reimbursable expenses 12.9   9.4 28.3 24.4  
Total contract drilling expenses (exclusive of depreciation) 201.7   197.1 535.6 592.4  
Depreciation 17.7   15.5 50.6 44.3  
General and administrative 0.0   0.0 0.0 0.0  
Business Combination, Acquisition-Related Cost, Expense 0.0     0.0    
Other Operating Income (Expense), Net       0.2 7.8  
Costs and Expenses 222.4   212.6 586.4 644.5  
Equity in earnings of ARO 0.0   0.0 0.0 0.0  
OPERATING INCOME 136.9   90.3 260.5 350.2  
Property and equipment, net (1,346.4)   (1,201.3) (1,346.4) (1,201.3)  
Capital expenditures 60.3   37.6 174.0 89.8  
Operating Segments | Jackups            
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) 171.2   216.7 550.4 614.6  
Reimbursable revenues 17.6   20.4 45.8 74.1  
Total operating revenues 188.8   237.1 596.2 688.7  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses 129.2   124.8 401.9 365.8  
Reimbursable expenses 16.5   18.9 42.4 69.6  
Total contract drilling expenses (exclusive of depreciation) 145.7   143.7 444.3 435.4  
Depreciation 16.2   15.3 48.9 42.6  
General and administrative 0.0   0.0 0.0 0.0  
Business Combination, Acquisition-Related Cost, Expense 0.0     0.0    
Other Operating Income (Expense), Net 0.0     0.0 0.0  
Costs and Expenses 161.9   159.0 493.2 478.0  
Equity in earnings of ARO 0.0   0.0 0.0 0.0  
OPERATING INCOME 26.9   78.1 103.0 210.7  
Property and equipment, net (641.9)   (628.9) (641.9) (628.9)  
Capital expenditures 35.1   28.9 79.7 138.9  
Operating Segments | ARO            
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) 144.9   156.8 399.2 431.4  
Reimbursable revenues 0.0   0.0 0.0 0.0  
Total operating revenues 144.9   156.8 399.2 431.4  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses 91.7   91.6 238.4 273.6  
Reimbursable expenses 0.0   0.0 0.0 0.0  
Total contract drilling expenses (exclusive of depreciation) 91.7   91.6 238.4 273.6  
Depreciation 28.8   28.4 75.7 86.6  
General and administrative 7.7   5.5 25.4 18.4  
Business Combination, Acquisition-Related Cost, Expense 0.0     0.0    
Other Operating Income (Expense), Net 0.0     0.0 0.0  
Costs and Expenses 128.2   125.5 339.5 378.6  
Equity in earnings of ARO 0.0   0.0 0.0 0.0  
OPERATING INCOME 16.7   31.3 59.7 52.8  
Property and equipment, net (1,311.3)   (1,199.7) (1,311.3) (1,199.7)  
Capital expenditures 69.5   10.9 141.1 33.0  
Operating Segments | Other            
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) 38.4   45.9 120.0 122.4  
Reimbursable revenues 7.1   9.8 35.1 25.8  
Total operating revenues 45.5   55.7 155.1 148.2  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses 20.8   16.3 70.9 49.7  
Reimbursable expenses 8.0   9.7 34.8 25.5  
Total contract drilling expenses (exclusive of depreciation) 28.8   26.0 105.7 75.2  
Depreciation 8.1   3.0 20.4 8.6  
General and administrative 0.0   0.0 0.0 0.0  
Business Combination, Acquisition-Related Cost, Expense 0.0     0.0    
Other Operating Income (Expense), Net 0.0     0.0 0.0  
Costs and Expenses 36.9   29.0 126.1 83.8  
Equity in earnings of ARO 0.0   0.0 0.0 0.0  
OPERATING INCOME 8.6   26.7 29.0 64.4  
Property and equipment, net (217.5)   (145.4) (217.5) (145.4)  
Capital expenditures 25.7   0.0 72.3 0.0  
Corporate, Non-Segment | Reconciling Items            
Segment Reporting [Line Items]            
Revenues (exclusive of reimbursable revenues) (144.9)   (156.8) (399.2) (431.4)  
Reimbursable revenues 0.0   0.0 0.0 0.0  
Total operating revenues (144.9)   (156.8) (399.2) (431.4)  
Operating expenses:            
Contract Drilling Expenses Exclusive of Depreciation and Reimbursable Expenses (50.6)   (52.8) (117.8) (160.3)  
Reimbursable expenses 0.0   0.0 0.0 0.0  
Total contract drilling expenses (exclusive of depreciation) (50.6)   (52.8) (117.8) (160.3)  
Depreciation (23.5)   (25.1) (61.0) (76.4)  
General and administrative 18.0   21.4 52.8 51.7  
Business Combination, Acquisition-Related Cost, Expense 15.5     40.5    
Other Operating Income (Expense), Net 0.0     0.0 0.0  
Costs and Expenses (40.6)   (56.5) (85.5) (185.0)  
Equity in earnings of ARO 3.5   (4.4) (13.9) (5.9)  
OPERATING INCOME (107.8)   (95.9) (299.8) (240.5)  
Property and equipment, net 1,257.9   1,140.9 1,257.9 1,140.9  
Capital expenditures $ (69.0)   $ (7.6) $ (139.1) $ (24.5)