Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Liability, Leases Not Commenced	$ 238.0
Operating Leases, Future Minimum Payments Due, Gross Rent, Current			$ 352.0
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Current			(7.7)
Operating Leases, Future Minimum Payments Due, Next Twelve Months			344.3
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	333.5
Operating Lease, Expense	$ 325.2
Minimum Remaining Lease Term	1 year
Maximum Remaining Lease Term	20 years
Short-term Lease, Cost	$ 13.8
Sublease Income	(12.9)
Lease, Cost	326.1
Operating Lease, Payments	334.1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 422.8
Operating Lease, Weighted Average Remaining Lease Term	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.26%
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 300.7
Lessee, Operating Lease, Liability, Payments, Due Year Three	267.5
Lessee, Operating Lease, Liability, Payments, Due Year Four	209.7
Lessee, Operating Lease, Liability, Payments, Due Year Five	183.5
Lessee, Operating Lease, Liability, Payments, Due after Year Five	716.1
Lessee, Operating Lease, Liability, Payments, Due	2,011.0
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	314.2
Operating Lease, Liability	1,696.8	$ 1,544.4
Operating Lease, Liability, Current	267.2		0.0
Operating Lease, Liability, Noncurrent	$ 1,429.6		0.0
Operating Leases, Future Minimum Payments, Gross Rent, Due in Two Years			324.3
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Two Years			(5.2)
Operating Leases, Future Minimum Payments, Due in Two Years			319.1
Operating Leases, Future Minimum Payments, Gross Rent, Due in Three Years			282.3
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Three Years			(2.2)
Operating Leases, Future Minimum Payments, Due in Three Years			280.1
Operating Leases, Future Minimum Payments, Gross Rent, Due in Four Years			242.5
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Four Years			(1.3)
Operating Leases, Future Minimum Payments, Due in Four Years			241.2
Operating Leases, Future Minimum Payments, Gross Rent, Due in Five Years			184.0
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Five Years			(0.6)
Operating Leases, Future Minimum Payments, Due in Five Years			183.4
Operating Leases, Future Minimum Payments, Gross Rent, Due Thereafter			714.6
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due Thereafter			(0.5)
Operating Leases, Future Minimum Payments, Due Thereafter			714.1
Operating Leases, Future Minimum Payments Due, Gross Rent			2,099.7
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals			(17.5)
Operating Leases, Future Minimum Payments Due			$ 2,082.2
Minimum Lease Term for Leases That Have Not Yet Commenced	4 years
Maximum Lease Term for Leases That Have Not Yet Commenced	15 years