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Asset Retirement Obligation - Schedule of Change in Asset Retirement Obligation (Details)
$ in Millions
9 Months Ended
Sep. 30, 2019
USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]  
As of December 31, 2018 $ 34.2
Accretion expense 1.9
Additions 0.3
Liabilities settled (1.5)
Foreign currency translation adjustments 0.1
As of September 30, 2019 $ 35.0