Unaudited Condensed Consolidated Statements of Partners' Capital - 3 months ended Mar. 31, 2020 - USD ($) $ in Millions	Total	General Partner	Limited Partners	Accumulated Other Comprehensive Loss
Beginning of Period at Dec. 31, 2019	$ 21.6	$ 12.0	$ 20.2	$ (10.6)
Increase (Decrease) in Partners' Capital [Roll Forward]
Other comprehensive income	(0.2)	0.0	0.0	(0.2)
Net loss	(14.4)	(0.3)	(14.1)	0.0
Settlement of tax withholdings on equity-based incentive compensation	(0.3)	0.0	(0.3)	0.0
Amortization of phantom units	0.3	0.0	0.3	0.0
End of Period at Mar. 31, 2020	$ 7.0	$ 11.7	$ 6.1	$ (10.8)