Investment in and Advances to Unconsolidated Affiliates Affiliate Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Affiliate Income Statement [Abstract]
Net revenue	$ 77.0	$ 72.2
Operating and SG&A expense	53.6	49.8
Depreciation and amortization	6.6	5.7
Total operating expense	60.2	55.5
Operating income	16.8	16.7
Interest and other expense, net	2.9	3.5
Net income	$ 13.9	$ 13.2