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Interest Expense, Net (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Interest Expense [Abstract] |  |  |
Interest on long-term debt | $ 354.2 | $ 327.7 | $ 342.2
Interest on short-term borrowings | 14.7 | 50.8 | 31.8
Debt discount/cost amortization | 9.1 | 8.3 | 7.7
Accounts receivable securitization fees | 2.6 | 2.6 | 2.6
Allowance for borrowed funds used and interest capitalized during construction | (7.0) | (7.5) | (9.1)
Debt-based post-in-service carrying charges | (14.6) | (18.7) | (35.0)
Other | 11.7 | 15.7 | 13.1
Total Interest Expense, net | $ 370.7 | $ 378.9 | $ 353.3

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