Leases (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Jan. 01, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Right-of-use asset recognized as non-cash asset addition	$ 8.7			$ 2.4	$ 3.6
Cash paid for amounts included in measurement of operating lease liability				3.0	2.7
Total operating lease expense		$ 2.7	$ 2.0	6.8	6.2
Operating lease expense		0.9	0.9	2.8	2.7
Operating lease revenues		$ 3.0	$ 3.6	$ 9.4	$ 10.4
Minimum
Lessee, Lease, Description [Line Items]
Operating leases remaining term, lessee		1 year		1 year
Operating leases remaining term, lessor		2 years		2 years
Maximum
Lessee, Lease, Description [Line Items]
Operating leases remaining term, lessee		11 years		11 years
Operating leases remaining term, lessor		10 years		10 years