Leases (Summary of Supplemental Cash Flow Information Related to Leases) (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases		$ 4.2	$ 5.0
Operating cash flows from finance leases		0.4
Financing cash flows from finance leases		1.2
ROU assets obtained in exchange for lease liabilities
Operating leases	[1]	4.1	$ 39.4
Finance leases		$ 7.5

[1] The nine months ended September 30, 2019 includes initial ROU assets of $29.2 million recognized upon adoption on January 1, 2019