Investment in and Advances to Unconsolidated Affiliates - Affiliate Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Investments in and Advances to Affiliates, Affiliate Balance Sheet [Abstract]
Current assets	$ 67.1	$ 24.0
Property and equipment, net	243.6	95.7
Other assets, net	235.4	106.7
Total assets	546.1	226.4
Current liabilities	87.2	21.2
Long-term debt	752.3	0.0
Other liabilities	7.5	0.0
Members' equity	(300.9)	205.2
Total liabilities and members' equity	$ 546.1	$ 226.4