Leases (Supplemental Cash Flow and Other Information) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 16.0	$ 48.7
Operating cash flows used for operating leases		49.2
Right-of-use assets obtained in exchange for operating lease obligations		$ 59.4
Weighted average remaining lease term - operating leases	7 years	7 years
Weighted average discount rate	3.00%	3.00%