Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease assets	$ 1,452.3		$ 1,452.3		$ 1,457.0
Short-term operating lease liabilities	182.2		182.2		168.3
Operating lease liabilities	$ 1,274.2		$ 1,274.2		$ 1,285.1
Weighted average remaining lease term	10 years 2 months 12 days		10 years 2 months 12 days
Weighted average discount rate	5.70%		5.70%
Variable lease costs	$ 14.6	$ 20.4	$ 36.7	$ 39.9
Cash paid for operating leases			199.0	195.5
Operating lease asset obtained in exchange for operating lease liability			116.4	252.5
Rental income	182.0	296.1	444.3	538.1
Operating expense
Lessee, Lease, Description [Line Items]
Operating lease costs	93.3	102.6	195.8	197.0
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Operating lease costs	$ 2.1	$ 2.3	$ 4.3	$ 4.4