Consolidated Balance Sheets (Parenthetical)	Sep. 30, 2014	Dec. 31, 2013
Partners' capital:
Class C convertible preferred unitholders issued (in units)	16,666,667	16,666,667
Class C convertible preferred unitholders outstanding (in units)	16,666,667	16,666,667
General partner, issued (in units)	0	51,036
General partner, outstanding (in units)	0	51,036
Class B convertible unitholders, issued (in units)	6,133,558	6,133,558
Class B convertible unitholders, outstanding (in units)	6,133,558	6,133,558
Limited Partners-Public Common [Member]
Partners' capital:
Limited partners unitholders, issued (in units)	51,694,835	51,483,263
Limited partners unitholders, outstanding (in units)	51,694,835	51,483,263
Limited Partners-Affiliated - Common [Member]
Partners' capital:
Limited partners unitholders, issued (in units)	7,145,866	7,145,866
Limited partners unitholders, outstanding (in units)	7,145,866	7,145,866