Leases - Components of Lease Expense and Other Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease expense	$ 34.7
Short-term lease expense	6.1
Variable lease expense	5.1
Total lease expense	45.9
Supplemental Cash Flows Information
Cash paid for amounts included in the measurement of operating lease liabilities	30.6
Operating ROU assets obtained in exchange for lease obligations	$ 14.4