Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Total income tax expense	$ 3.0	$ 0.2
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax expense (benefit) at statutory federal rate (35%)	$ 0.4	(160.5)
Federal statutory tax rate	35.00%
State income taxes benefit, net of federal tax benefit	$ 0.0	(14.9)
Income tax expense from partnership	0.5	1.0
Unit-based compensation	2.3	0.0
Non-deductible expense related to asset impairment	0.0	173.9
Other	(0.2)	0.7
Total income tax expense	$ 3.0	$ 0.2