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Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Property, Plant and Equipment [Line Items] |  |  |
Depreciation | $ 820.4 | $ 756.9 | $ 685.0
Regulatory Deferral - Joint Venture | 58.9 | 12.5 | 11.0
Capitalized Computer Software, Amortization | 85.2 | 77.5 | 53.1
Capitalized Computer Software, Gross | 236.1 | 205.6 |
Capitalized Cloud Computing, Amortization | 17.7 | 12.6 | $ 11.1
Capitalized Cloud Computing, Gross | $ 77.5 | $ 32.2 |

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- Definition Amount of expense for amortization of capitalized computer software costs. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 985 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481283/985-20-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 985 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481283/985-20-50-1 + Details
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- Definition Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 350 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482665/350-30-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 985 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481283/985-20-50-2 + Details
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