Units Outstanding

3 Months Ended

Mar. 31, 2015

Units Outstanding [Abstract]

Units Outstanding

13. Units Outstanding

Changes in limited partnership units outstanding during the three-month period ended March 31, 2015 were as follows:

Outstanding as of December 31, 2014	273,040,452
Options exercised	228,816
Units issued	27,755
Units retired	(689,430	)
Outstanding as of March 31, 2015	272,607,593

During the first quarter of 2015, we purchased 400 AB Units in private transactions and retired them.