Leases Components of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases expenses [Abstract]
Operating lease cost including variable costs	$ 92.0	$ 183.4
Short-term lease costs	9.4	14.9
Less: sublease income	1.7	4.0
Net lease cost	$ 99.7	$ 194.3