Lease Accounting (Lease Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease cost	$ 3.9	$ 3.5
Finance lease cost
Amortization of leased assets	0.3	0.3
Interest on lease liabilities	0.0	0.0
Net lease costs	$ 4.2	$ 3.8