Investment in and Advances to Unconsolidated Affiliates Affiliate Income Statement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Affiliate Income Statement [Abstract]
Net revenue	$ 105.2	$ 128.4	$ 322.1	$ 340.9
Operating and SG&A expense	76.4	97.9	240.5	263.3
Depreciation and amortization	5.9	5.2	19.0	16.1
Total operating expense	82.3	103.1	259.5	279.4
Operating income	22.9	25.3	62.6	61.5
Interest and other, net	(1.0)	0.3	(5.6)	(4.7)
Net income	$ 21.9	$ 25.6	$ 57.0	$ 56.8