Leases (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Finance Lease, Right-of-Use Asset	$ 3.6	$ 3.6
Finance Lease, Liability, Current	0.4	0.4
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	17.6	17.6
Finance Lease, Liability, Payments, Due in Next Rolling Twelve Months	0.4	0.4
Lessee, Operating Lease, Liability, Payments, Due Year Two	29.4	29.4
Operating Lease, Payments	8.8	17.7	$ 0.0
Finance Lease, Principal Payments	0.1	1.1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	23.7	39.4
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 0.2	$ 0.8
Operating Lease, Weighted Average Remaining Lease Term	5 years 3 months 18 days	5 years 3 months 18 days
Finance Lease, Weighted Average Remaining Lease Term	3 years 7 months 6 days	3 years 7 months 6 days
Operating Lease, Weighted Average Discount Rate, Percent	4.10%	4.10%
Finance Lease, Weighted Average Discount Rate, Percent	2.58%	2.58%
Operating Lease, Right-of-Use Asset	$ 117.3	$ 117.3		$ 114.1	$ 0.0
Operating Lease, Liability, Current	29.5	29.5		29.8	0.0
Operating Lease, Liability, Noncurrent	73.0	73.0		$ 69.7	$ 0.0
Operating Lease, Expense	8.3	18.7	$ 0.0
Finance Lease, Right-of-Use Asset, Amortization	0.2	0.6
Finance Lease, Liability, Payments, Due in Rolling Year Two	0.9	0.9
Lessee, Operating Lease, Liability, Payments, Due Year Three	19.4	19.4
Finance Lease, Liability, Payments, Due in Rolling Year Three	0.8	0.8
Lessee, Operating Lease, Liability, Payments, Due Year Four	13.7	13.7
Finance Lease, Liability, Payments, Due in Rolling Year Four	0.7	0.7
Lessee, Operating Lease, Liability, Payments, Due Year Five	10.1	10.1
Finance Lease, Liability, Payments, Due in Rolling Year Five	0.2	0.2
Lessee, Operating Lease, Liability, Payments, Due after Year Five	24.1	24.1
Finance Lease, Liability, Payments, Due in Rolling after Year Five	0.0	0.0
Operating Lease, Liability	114.3	114.3
Finance Lease, Liability, Payments, Due	3.0	3.0
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(11.8)	(11.8)
Finance Lease, Liability, Undiscounted Excess Amount	(0.1)	(0.1)
Operating Lease, Liability	102.5	102.5
Lease, Cost	8.5	19.3
Finance Lease, Liability, Noncurrent	2.5	2.5
Finance Lease, Liability	$ 2.9	$ 2.9