Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 0.4	$ 0.1
Common units, issued	68,555,305	18,640,366.7
Common units, outstanding	68,555,305	18,640,367
Preferred units, issued	60,718,245	0
Preferred units, outstanding	60,718,245	0
CMLP
Allowance for doubtful accounts	$ 0.4	$ 0.1
Common units, issued	0	187,965,105
Common units, outstanding	0	187,965,105
Preferred units, issued	0	17,917,870
Preferred units, outstanding	0	17,917,870