Operating Leases - Cost Components of Operating Leases (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 29.6	$ 58.4
Variable lease cost	2.8	6.5
Short-term lease cost	6.2	13.5
Total	38.6	78.4
Leased Facilities and Equipment
Lessee, Lease, Description [Line Items]
Operating lease cost	26.1	51.8
Variable lease cost	2.2	5.5
Short-term lease cost	0.0	0.0
Total	28.3	57.3
Leased Vehicles
Lessee, Lease, Description [Line Items]
Operating lease cost	3.5	6.6
Variable lease cost	0.6	1.0
Short-term lease cost	6.2	13.5
Total	$ 10.3	$ 21.1