Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Leases [Abstract]
Operating Lease, Payments	$ (62.0)
Short-term Lease, Cost	3.3
Variable Lease, Cost	$ 4.5
leases not yet commenced	50
Operating Leases, Rent Expense		$ 85.7
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 208.0		$ 191.1
Finance Lease, Liability, Payments, Due Next Twelve Months	10.9		8.6
Finance Lease, Liability, Payments, Due	92.5
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(38.1)
Finance Lease, Liability, Undiscounted Excess Amount	(36.1)
Operating Lease, Right-of-Use Asset	717.9
Operating Lease, Liability, Current	263.4		0.0
Operating Lease, Liability, Noncurrent	502.4		0.0
Operating Lease, Liability	765.8
Finance Lease, Right-of-Use Asset	43.6
Finance Lease, Liability, Current	7.7		7.9
Finance Lease, Liability, Noncurrent	48.7		51.0
Finance Lease, Liability	$ 56.4
Operating Lease, Weighted Average Remaining Lease Term	5 years 3 months
Operating Lease, Cost	$ 61.2
Finance Lease, Right-of-Use Asset, Amortization	1.4
Finance Lease, Interest Expense	$ 0.8
Finance Lease, Weighted Average Remaining Lease Term	6 years 7 months
Operating Lease, Weighted Average Discount Rate, Percent	4.00%
Finance Lease, Weighted Average Discount Rate, Percent	4.60%
Operating Leases, Future Minimum Payments, Due in Two Years	$ 196.1		145.4
Finance Lease, Liability, Payments, Due Year Two	13.8		8.0
Operating Leases, Future Minimum Payments, Due in Three Years	108.8		107.0
Finance Lease, Liability, Payments, Due Year Three	12.0		6.7
Operating Leases, Future Minimum Payments, Due in Four Years	75.6		80.9
Finance Lease, Liability, Payments, Due Year Four	10.8		6.0
Operating Leases, Future Minimum Payments, Due in Five Years	54.0		61.5
Finance Lease, Liability, Payments, Due Year Five	10.7		6.5
Operating Leases, Future Minimum Payments, Due Thereafter	161.4		155.6
Finance Lease, Liability, Payments, Due after Year Five	34.3		$ 23.1
Lessee, Operating Lease, Liability, Payments, Due	803.9
Lease, Cost	2.2
Finance Lease, Interest Payment on Liability	(0.5)
Finance Lease, Principal Payments	(3.0)
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	35.7
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 0.0