Investments in and Advances to Affiliates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	50.00%
Revenue from affiliates	$ 15.5	$ 11.7	$ 9.3
Expenses from affiliates	60.1	53.1	54.1
Due from affiliates	3.6	1.9
Due to affiliates	1.2	0.1
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	3.3
Income from affiliates, classified in cost of sales	4.0
Equity in income of unconsolidated affiliates	$ 0.0	$ (5.2)	$ (6.7)