v3.25.4
Other Commitments and Contingencies (Contractual Obligation, Fiscal Year Maturity Schedule) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Long-term Purchase Commitment [Line Items]    
Long-term Debt, Future Minimum Payments Due $ 15,345.0  
Long-term Debt, Future Minimum Payments Due, Next Twelve Months 0.0  
Long-term Debt, Future Minimum Payments, Due in Two Years 1,090.0  
Long-term Debt, Future Minimum Payments, Due in Three Years 1,055.0  
Long-term Debt, Future Minimum Payments, Due in Four Years 1,350.0  
Long-term Debt, Future Minimum Payments, Due in Five Years 1,000.0  
Long-term Debt, Future Minimum Payments, Due Thereafter 10,850.0  
Interest Payments on Long-term Debt, Future Minimum Payments Due 12,361.2  
Interest Payments on Long-term Debt, Future Minimum Payments Due, Next Twelve Months 729.1  
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Two Years 725.1  
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Three Years 675.0  
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Four Years 647.3  
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Five Years 575.9  
Interest Payments on Long-term Debt, Future Minimum Payments, Due Thereafter 9,008.8  
Finance Leases, Future Minimum Payments Due 497.9  
Finance Leases, Future Minimum Payments Due, Next Twelve Months 32.6  
Finance Leases, Future Minimum Payments Due in Two Years 27.4  
Finance Leases, Future Minimum Payments Due in Three Years 26.2  
Finance Leases, Future Minimum Payments Due in Four Years 21.3  
Finance Leases, Future Minimum Payments Due in Five Years 22.3  
Finance Leases, Future Minimum Payments Due Thereafter 368.1  
Operating Leases, Future Minimum Payments Due 30.5  
Operating Leases, Future Minimum Payments Due, Next Twelve Months 10.7  
Operating Leases, Future Minimum Payments, Due in Two Years 5.1  
Operating Leases, Future Minimum Payments, Due in Three Years 3.8  
Operating Leases, Future Minimum Payments, Due in Four Years 3.2  
Operating Leases, Future Minimum Payments, Due in Five Years 2.1  
Operating Leases, Future Minimum Payments, Due Thereafter 5.6  
Energy Commodity Contracts, Future Minimum Payments Due 476.9  
Energy Commodity Contracts, Future Minimum Payments Due, Next Twelve Months 315.9  
Energy Commodity Contracts, Future Minimum Payments, Due in Two Years 116.7  
Energy Commodity Contracts, Future Minimum Payments, Due in Three Years 9.3  
Energy Commodity Contracts, Future Minimum Payments, Due in Four Years 7.6  
Energy Commodity Contracts, Future Minimum Payments, Due in Five Years 4.6  
Energy Commodity Contracts, Future Minimum Payments, Due Thereafter 22.8  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments Due 2,829.1  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments Due, Next Twelve Months 809.5  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Two Years 879.3  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Three Years 482.3  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Four Years 326.5  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Five Years 156.6  
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due Thereafter 174.9  
Service Obligations, IT Service Obligations, Future Minimum Payments Due 322.1  
Service Obligations, IT Service Obligations, Future Minimum Payments Due, Next Twelve Months 98.3  
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Two Years 81.8  
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Three Years 61.7  
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Four Years 43.0  
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Five Years 37.3  
Service Obligations, IT Service Obligations, Future Minimum Payments, Due Thereafter 0.0  
Plant equipment purchase obligations, Future Minimum Payments, Due Thereafter 0.0  
Plant equipment purchase obligations, Future Minimum Payments, Due in Five Years 0.0  
Plant equipment purchase obligations, Future Minimum Payments, Due in Four Years 0.0  
Plant equipment purchase obligations, Future Minimum Payments, Due in Three Years 5.3  
Plant equipment purchase obligations, Future Minimum Payments, Due in Two Years 10.4  
Plant equipment purchase obligations, Future Minimum Payments Due, Next Twelve Months 87.6  
Plant equipment purchase obligations, Future Minimum Payments Due 103.3  
Other Liabilities, Future Minimum Payments Due 120.3  
Other Liabilities, Future Minimum Payments Due, Next Twelve Months 74.0  
Other Liabilities, Future Minimum Payments, Due in Two Years 10.1  
Other Liabilities, Future Minimum Payments, Due in Three Years 9.5  
Other Liabilities, Future Minimum Payments, Due in Four Years 8.4  
Other Liabilities, Future Minimum Payments, Due in Five Years 8.0  
Other Liabilities, Future Minimum Payments, Due Thereafter 10.3  
Total Future Contractual Obligations Due 32,086.3  
Total Future Contractual Obligations Due, Next Twelve Months 2,157.7  
Total Future Contractual Obligations, Due in Two Years 2,945.9  
Total Future Contractual Obligations, Due in Three Years 2,328.1  
Total Future Contractual Obligations, Due in Four Years 2,407.3  
Total Future Contractual Obligations, Due in Five Years 1,806.8  
Total Future Contractual Obligations, Due Thereafter 20,440.5  
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net (141.5) $ (95.5)
Finance Lease, Liability, Undiscounted Excess Amount (223.9)  
Lessee, Operating Lease, Liability, Undiscounted Excess Amount $ (3.6)