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v3.20.4

Other Commitments and Contingencies (Contractual Obligation, Fiscal Year Maturity Schedule) (Details) - USD ($) $ in Millions | Feb. 09, 2021 | Feb. 01, 2021 | Dec. 31, 2020 | Dec. 31, 2019
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Long-term Purchase Commitment [Line Items] |  |  |  |
Long-term Debt, Future Minimum Payments Due |  |  | $ 9,135.0 |
Long-term Debt, Future Minimum Payments Due, Next Twelve Months |  |  | 0.0 |
Long-term Debt, Future Minimum Payments, Due in Two Years |  |  | 30.0 |
Long-term Debt, Future Minimum Payments, Due in Three Years |  |  | 0.0 |
Long-term Debt, Future Minimum Payments, Due in Four Years |  |  | 0.0 |
Long-term Debt, Future Minimum Payments, Due in Five Years |  |  | 1,260.0 |
Long-term Debt, Future Minimum Payments, Due Thereafter |  |  | 7,845.0 |
Interest Payments on Long-term Debt, Future Minimum Payments Due |  |  | 6,046.3 |
Interest Payments on Long-term Debt, Future Minimum Payments Due, Next Twelve Months |  |  | 336.3 |
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Two Years |  |  | 335.7 |
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Three Years |  |  | 334.1 |
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Four Years |  |  | 334.1 |
Interest Payments on Long-term Debt, Future Minimum Payments, Due in Five Years |  |  | 334.1 |
Interest Payments on Long-term Debt, Future Minimum Payments, Due Thereafter |  |  | 4,372.0 |
Finance Leases, Future Minimum Payments Due |  |  | 264.7 |
Finance Leases, Future Minimum Payments Due, Next Twelve Months |  |  | 32.7 |
Finance Leases, Future Minimum Payments Due in Two Years |  |  | 32.2 |
Finance Leases, Future Minimum Payments Due in Three Years |  |  | 28.8 |
Finance Leases, Future Minimum Payments Due in Four Years |  |  | 20.8 |
Finance Leases, Future Minimum Payments Due in Five Years |  |  | 16.1 |
Finance Leases, Future Minimum Payments Due Thereafter |  |  | 134.1 |
Operating Leases, Future Minimum Payments Due |  |  | 48.0 |
Operating Leases, Future Minimum Payments Due, Next Twelve Months |  |  | 11.7 |
Operating Leases, Future Minimum Payments, Due in Two Years |  |  | 5.2 |
Operating Leases, Future Minimum Payments, Due in Three Years |  |  | 4.7 |
Operating Leases, Future Minimum Payments, Due in Four Years |  |  | 4.5 |
Operating Leases, Future Minimum Payments, Due in Five Years |  |  | 3.7 |
Operating Leases, Future Minimum Payments, Due Thereafter |  |  | 18.2 |
Energy Commodity Contracts, Future Minimum Payments Due |  |  | 42.1 |
Energy Commodity Contracts, Future Minimum Payments Due, Next Twelve Months |  |  | 42.1 |
Energy Commodity Contracts, Future Minimum Payments, Due in Two Years |  |  | 0.0 |
Energy Commodity Contracts, Future Minimum Payments, Due in Three Years |  |  | 0.0 |
Energy Commodity Contracts, Future Minimum Payments, Due in Four Years |  |  | 0.0 |
Energy Commodity Contracts, Future Minimum Payments, Due in Five Years |  |  | 0.0 |
Energy Commodity Contracts, Future Minimum Payments, Due Thereafter |  |  | 0.0 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments Due |  |  | 1,495.6 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments Due, Next Twelve Months |  |  | 468.7 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Two Years |  |  | 422.5 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Three Years |  |  | 256.0 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Four Years |  |  | 150.5 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due in Five Years |  |  | 56.2 |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments, Due Thereafter |  |  | 141.7 |
Service Obligations, IT Service Obligations, Future Minimum Payments Due |  |  | 240.3 |
Service Obligations, IT Service Obligations, Future Minimum Payments Due, Next Twelve Months |  |  | 74.9 |
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Two Years |  |  | 74.0 |
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Three Years |  |  | 38.1 |
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Four Years |  |  | 30.5 |
Service Obligations, IT Service Obligations, Future Minimum Payments, Due in Five Years |  |  | 22.8 |
Service Obligations, IT Service Obligations, Future Minimum Payments, Due Thereafter |  |  | 0.0 |
Service Obligations, Other Service Obligations, Future Minimum Payments Due |  |  | 12.6 |
Service Obligations, Other Service Obligations, Future Minimum Payments Due, Next Twelve Months |  |  | 12.6 |
Service Obligations, Other Service Obligations, Future Minimum Payments, Due in Two Years |  |  | 0.0 |
Service Obligations, Other Service Obligations, Future Minimum Payments, Due in Three Years |  |  | 0.0 |
Service Obligations, Other Service Obligations, Future Minimum Payments, Due in Four Years |  |  | 0.0 |
Service Obligations, Other Service Obligations, Future Minimum Payments, Due in Five Years |  |  | 0.0 |
Service Obligations, Other Service Obligations, Future Minimum Payments, Due Thereafter |  |  | 0.0 |
Other Liabilities, Future Minimum Payments Due |  |  | 116.9 |
Other Liabilities, Future Minimum Payments Due, Next Twelve Months |  |  | 26.0 |
Other Liabilities, Future Minimum Payments, Due in Two Years |  |  | 0.8 |
Other Liabilities, Future Minimum Payments, Due in Three Years |  |  | 90.1 |
Other Liabilities, Future Minimum Payments, Due in Four Years |  |  | 0.0 |
Other Liabilities, Future Minimum Payments, Due in Five Years |  |  | 0.0 |
Other Liabilities, Future Minimum Payments, Due Thereafter |  |  | 0.0 |
Total Future Minimum Lease Payments Due |  |  | 17,401.5 |
Total Future Minimum Lease Payments Due, Next Twelve Months |  |  | 1,005.0 |
Total Future Minimum Lease Payments, Due in Two Years |  |  | 900.4 |
Total Future Minimum Lease Payments, Due in Three Years |  |  | 751.8 |
Total Future Minimum Lease Payments, Due in Four Years |  |  | 540.4 |
Total Future Minimum Lease Payments, Due in Five Years |  |  | 1,692.9 |
Total Future Minimum Lease Payments, Due Thereafter |  |  | 12,511.0 |
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net |  |  | (86.9) | $ (70.5)
Finance Leases, Future Minimum Payments, Interest Included in Payments |  |  | 69.7 |
Operating Leases, Future Minimum Payaments, Interest Included in Payments |  |  | 7.8 |
Subsequent Event |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Service Obligations, Pipeline Service Obligations, Future Minimum Payments Due |  | $ 638.6 |  |
Service Obligations, Other Service Obligations, Future Minimum Payments Due | $ 12.1 |  |  |
Fleet Lease |  |  |  |
Long-term Purchase Commitment [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Next Twelve Months |  |  | 30.0 |
Operating Leases, Future Minimum Payments, Due in Two Years |  |  | 27.7 |
Operating Leases, Future Minimum Payments, Due in Three Years |  |  | 24.9 |
Operating Leases, Future Minimum Payments, Due in Four Years |  |  | 22.0 |
Operating Leases, Future Minimum Payments, Due in Five Years |  |  | 19.0 |
Operating Leases, Future Minimum Payments, Due Thereafter |  |  | $ 21.5 |

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