Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
2019	$ 103.4
2020	79.9
2021	57.5
2022	41.0
2023	32.0
Later years	130.3
Future Minimum Payments Due	444.1
Rent expense	121.9	$ 106.0	$ 96.0
Facilities
Operating Leased Assets [Line Items]
2019	51.7
2020	46.2
2021	39.5
2022	33.8
2023	29.4
Later years	130.3
Future Minimum Payments Due	330.9
Vehicles
Operating Leased Assets [Line Items]
2019	18.3
2020	11.6
2021	7.6
2022	5.3
2023	2.3
Later years	0.0
Future Minimum Payments Due	45.1
Other
Operating Leased Assets [Line Items]
2019	33.4
2020	22.1
2021	10.4
2022	1.9
2023	0.3
Later years	0.0
Future Minimum Payments Due	$ 68.1