Leases - Components of Lease Expense and Other Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease expense	$ 35.0	$ 69.7
Short-term lease expense	6.0	12.1
Variable lease expense	4.8	9.9
Total lease expense	$ 45.8	91.7
Supplemental Cash Flows Information
Cash paid for amounts included in the measurement of operating lease liabilities		64.8
Operating ROU assets obtained in exchange for lease obligations		$ 69.7