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Fair Value Measurements - Summary of Carrying Value and Estimated Fair Value of Long-Term Debt (Details) - Level 2 - Recurring basis - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Long-term debt excluding finance lease liabilities, carrying value $ 2,650.5 $ 2,650.4
Long-term debt excluding finance lease liabilities, estimated fair value $ 2,895.0 $ 2,902.2