Leases and Commitments (Minimum Rental Commitments and Purchase Obligations) (Details) $ in Millions	Dec. 31, 2017 USD ($)
2018, Leases	$ 60.2
2019, Leases	49.5
2020, Leases	39.0
2021, Leases	29.2
2022, Leases	27.1
Later years, Leases	66.6
Sublease rental income, Leases	(75.5)
Total, Leases	196.1
2018, Purchase Obligations	190.1
2019, Purchase Obligations	142.0
2020, Purchase Obligations	79.3
2021, Purchase Obligations	39.2
2022, Purchase Obligations	19.9
Later years, Purchase Obligations	8.6
Total, Purchase Obligations	$ 479.1