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Derivative Financial Instruments Cross Currency Swap (Details) $ in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019 USD ($)	Dec. 01, 2016 AUD ($)
Derivative [Line Items]
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), before Reclassification and Tax		$ 0.1
Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, before Tax		$ (0.1)
Intercompany GRail Loan [Member]
Derivative [Line Items]
Debt Instrument, Face Amount			$ 248.9
Cross-currency swap contract [Member] \| Net Investment Hedging [Member]
Derivative [Line Items]
Settlement Date		Jun. 30, 2021
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred		$ (0.4)
Cross-currency swap contract [Member] \| Fair Value Hedging [Member]
Derivative [Line Items]
Settlement Date		Jun. 30, 2021
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred		$ (0.2)
Cross-currency swap contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Settlement Date	Jun. 30, 2019