Accrued Liabilities - Third Parties - Schedule of Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Transportation, project engineering	$ 1.7	$ 3.0
Property taxes	4.9	0.3
FERC accrual	0.0	1.7
Professional fees	1.2	1.2
Other accrued liabilities	0.1	0.6
Accrued liabilities - third parties	$ 7.9	$ 6.8