Leases - Lease Cost and Other Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Finance leases
Amortization of ROU assets	$ 2.1
Interest on lease liabilities	0.5
Operating leases	8.4
Short-term lease cost	0.9
Variable lease cost	1.0
Total lease cost	12.9
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases	0.5
Operating cash flows from operating leases	8.6
Financing cash flows from finance leases	2.3
Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract]
ROU assets obtained in exchange for new finance lease liabilities	5.4
ROU assets obtained in exchange for new operating lease liabilities	$ 3.8
Finance leases
Remaining lease term (in years)	7 years 9 months 18 days
Discount rate	5.50%
Operating leases
Remaining lease term (in years)	5 years 1 month
Discount rate	5.60%