Leases (Narrative) (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use asset recognized as non-cash asset addition	$ 8.7	$ 2.8	$ 6.1
Cash paid for amounts included in measurement of operating lease liability		3.9	3.8
Total operating lease expense		6.8	8.5
Operating lease expense		3.8	3.8
Operating lease revenues		$ 12.6	$ 13.9
Minimum
Lessee, Lease, Description [Line Items]
Operating leases, remaining term, lessee		1 year
Operating lease remaining term, lessor		2 years
Maximum
Lessee, Lease, Description [Line Items]
Operating leases, remaining term, lessee		11 years
Operating lease remaining term, lessor		10 years