Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Land	$ 1.4	$ 1.4
Building and improvements	20.2	19.5
Pipeline and equipment	589.7	572.4
Other	6.0	5.6
Property, plant and equipment, gross	617.3	598.9
Accumulated depreciation, and amortization	(239.5)	(216.2)
Property plant and equipment excluding construction in progress	377.8	382.7
Construction in progress	20.2	10.2
Property, plant and equipment, net	398.0	392.9
Assets under capital lease	22.8	$ 22.8
Accumulated depreciation	$ 1.6
Building and Improvements | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Building and Improvements | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	40 years
Pipeline and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Pipeline and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	30 years
Other | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	5 years
Other | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	25 years