Leases (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Operating lease cost	$ 78.4
Short-term lease cost	5.1
Sublease income	(2.1)
Total lease cost	81.4
Cash paid for amounts included in the measurement of lease liabilities	79.4
Right-of-use assets obtained in exchange for lease obligations	$ 1.1
Weighted-average remaining lease term	7 years
Weighted-average discount rate	4.47%
Future minimum lease payments 2019	$ 327.1
Future minimum lease payments 2020	303.0
Future minimum lease payments 2021	261.1
Future minimum lease payments 2022	212.4
Future minimum lease payments 2023	157.8
Future minimum lease payments Thereafter	557.2
Total future minimum lease payments	1,818.6
Less: imputed interest	(332.0)
Present value of future minimum lease payments	1,486.6
Less: current portion of operating leases	263.0	$ 0.0
Non-current operating leases	$ 1,223.6	0.0
Rent obligations 2019		352.0
Sublease rental income 2019		(7.7)
Net rent 2019		344.3
Rent obligations 2020		324.3
Sublease rental income 2020		(5.2)
Net rent 2020		319.1
Rent obligations 2021		282.3
Sublease rental income 2021		(2.2)
Net rent 2021		280.1
Rent obligations 2022		242.5
Sublease rental income 2022		(1.3)
Net rent 2022		241.2
Rent obligations 2023		184.0
Sublease rental income 2023		(0.6)
Net rent 2023		183.4
Rent obligations Thereafter		714.6
Sublease rental income thereafter		(0.5)
Net rent thereafter		714.1
Rent obligations- Total future min lease payments		2,099.7
Sublease rental income- Total future min lease payments		(17.5)
Net rent- Total future min lease payments		$ 2,082.2
Additional operating leases ($) that have not yet commenced that will commence in 2019 with lease terms of 5 to 15 years	180

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