Discontinued Operations and Assets Held for Sale - Components Reflected in Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of California Discontinued Entities	$ 13.2	$ 0.0	$ 13.2	$ 0.0
Income from non-controlling interest	0.0	$ 0.0	8.1	$ 0.0
California Discontinued Entities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of California Discontinued Entities			(41.2)
California Discontinued Entities | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0.0		32.5
Cost of goods sold	0.0		3.8
Operating expenses	(1.0)		(8.8)
General and administrative expenses	0.0		(1.1)
Other operating expense, net	0.0		0.3
Interest income	0.0		3.0
Loss on sale of California Discontinued Entities	0.0		(41.2)
Loss from discontinued operations before taxes	(1.0)		(11.5)
Income tax benefit	(0.2)		(2.5)
Loss from discontinued operations, net of tax	$ (0.8)		$ (9.0)
Non-controlling interest					$ 10.5