Units Outstanding (Tables)

6 Months Ended

Jun. 30, 2015

Limited Partners' Capital Account [Abstract]

Changes in units outstanding

Changes in limited partnership units outstanding during the six-month period ended June 30, 2015 were as follows:

Outstanding as of December 31, 2014	273,040,452
Options exercised	526,201
Units issued	207,945
Units retired	(801,673	)
Balance as of June 30, 2015	272,972,925