Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2014	Dec. 31, 2013
Common Units
Units issued	202,532,920	188,739,474
Units outstanding	202,532,920	188,739,474
Class B Units
Units issued	13,725,843	13,188,705
Units outstanding	13,725,843	13,188,705
Class C Units
Units issued	0	11,888,247
Units outstanding	0	11,888,247