Operations and Significant Accounting Policies - Lease Maturities (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2019		$ 4.2
2020		7.9
2021		6.1
2022		4.9
2023		3.1
Thereafter		9.4
Total Lease Payments Due		35.6
Less: Imputed Interest		4.4
Total Lease Obligations		31.2
Operating Lease Liabilities	[1]	$ 7.2	$ 0.0
Other Current Liabilities		us-gaap:OperatingLeaseLiabilityCurrent
Operating Lease Liabilities		$ 24.0	0.0
Other Non-Current Liabilities		us-gaap:OperatingLeaseLiabilityNoncurrent
Less: Current Lease Obligations	[1]	$ 7.2	0.0
Long-term Lease Obligations		$ 24.0	$ 0.0

[1] See Leases.