Debt, Senior Notes, Total Debt Maturities and Operating Lease Commitments (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument, Receivables Financing Agreement [Abstract]
Premium paid on senior notes		$ 0.0	$ 29.7	$ 0.0
Total Debt Maturities [Abstract]
Debt maturities, 2019		6.9
Debt maturities, 2020		7.4
Debt maturities, 2021		7.7
Debt maturities, 2022		7.8
Debt maturities, 2023		8.0
Debt maturities, thereafter		1,634.3
Operating Lease Commitments [Abstract]
Annual rental payments for operating leases		31.7	$ 30.8	32.3
Future minimum rental payments for operating leases, 2019		25.8
Future minimum rental payments for operating leases, 2020		19.5
Future minimum rental payments for operating leases, 2021		13.9
Future minimum rental payments for operating leases, 2022		7.7
Future minimum rental payments for operating leases, 2023		5.4
Future minimum rental payments for operating leases, thereafter		$ 9.4
Senior Notes [Member]
Debt Instrument, Receivables Financing Agreement [Abstract]
Aggregate principal amount	$ 604.6			$ 575.0
Percentage of principal amount redeemed	105.156%
Accrued and unpaid interest	$ 10.2
Write-off of unamortized debt issuance costs	15.8
Premium paid on senior notes	$ 29.7