Operating Leases - Cost Components of Operating Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 28.8
Variable lease cost	3.7
Short-term lease cost	7.3
Total	39.8
Leased Facilities and Equipment
Lessee, Lease, Description [Line Items]
Operating lease cost	25.7
Variable lease cost	3.3
Short-term lease cost	0.0
Total	29.0
Leased Vehicles
Lessee, Lease, Description [Line Items]
Operating lease cost	3.1
Variable lease cost	0.4
Short-term lease cost	7.3
Total	$ 10.8