Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease, Liability, Leases Not Commenced	$ 52.0
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	322.9
Operating Lease, Expense	$ 318.5	$ 325.2
Minimum Remaining Lease Term	1 year
Maximum Remaining Lease Term	19 years
Short-term Lease, Cost	$ 10.6	13.8
Sublease Income	(15.8)	(12.9)
Lease, Cost	313.3	326.1
Operating Lease, Payments	335.7	334.1
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 274.4	$ 422.8
Operating Lease, Weighted Average Remaining Lease Term	8 years	8 years
Operating Lease, Weighted Average Discount Rate, Percent	4.00%	4.26%
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 302.6
Lessee, Operating Lease, Liability, Payments, Due Year Three	241.2
Lessee, Operating Lease, Liability, Payments, Due Year Four	212.2
Lessee, Operating Lease, Liability, Payments, Due Year Five	194.7
Lessee, Operating Lease, Liability, Payments, Due after Year Five	735.2
Lessee, Operating Lease, Liability, Payments, Due	2,008.8
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	299.3
Operating Lease, Liability	1,709.5		$ 1,544.4
Operating Lease, Liability, Current	268.5	$ 267.2
Operating Lease, Liability, Noncurrent	$ 1,441.0	$ 1,429.6
Minimum Lease Term for Leases That Have Not Yet Commenced	1 year
Maximum Lease Term for Leases That Have Not Yet Commenced	10 years