Income Taxes - Deferred Tax and NOL (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets
Net operating loss carryforward	$ 16.4	$ 16.4
Valuation allowance	(5.3)	(3.5)
Net deferred income tax asset	11.1	12.9
Deferred income tax liabilities
Investment in partnership	(11.1)	(12.9)
Property and equipment	(0.5)	(0.5)
Deferred income tax liability	(11.6)	(13.4)
Net deferred income tax liability	$ (0.5)	$ (0.5)