Financing - Minimum Principal Payments (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
2019		$ 455.3
2020		0.0
2021		750.0
2022		125.7
2023		0.0
Thereafter		1,450.0
Long-term debt	[1]	2,781.0
Debt discounts, premiums and issuance costs		17.0	$ 18.0
Long-term Debt		3,430.3	4,056.2
Term loan
Debt Instrument [Line Items]
2019		400.0
2020		0.0
2021		0.0
2022		125.7
2023		0.0
Thereafter		0.0
Long-term debt	[1]	525.7
Senior Notes
Debt Instrument [Line Items]
2019		55.3
2020		0.0
2021		750.0
2022		0.0
2023		0.0
Thereafter		1,450.0
Long-term debt	[1]	2,255.3
Commercial Paper
Debt Instrument [Line Items]
Long-term Debt		663.3
Other
Debt Instrument [Line Items]
Long-term Debt		$ 3.0	$ 3.4

[1] Not included in the table above are net discounts, premiums and issuance costs associated with the Registered Notes, which totaled $17 million as of December 31, 2018, and have been recorded as an offset to the carrying amount of the related debt in the accompanying Consolidated Balance Sheet as of December 31, 2018. In addition, the table above does not include principal balances of $663.3 million under the Commercial Paper Programs and other financing balances of $3 million.