Operating Leases (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Leases [Abstract]
Operating lease expenses	$ 53.2	$ 54.3	$ 46.9
Sublease income	$ 0.4	$ 1.0	$ 10.9