Income per Unit

The following is a summary of basic and diluted income per unit (in thousands, except unit and per unit amounts):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2015		2014		2015		2014
Net income available to common unitholders	$	38,116	$	111,586	$	261,302	$	188,848
Weighted average units outstanding—basic	138,467,947		138,308,130		138,481,046		135,381,624
Potentially dilutive common units:
Stock options	19,983		52,629		20,629		46,649
Unvested incentive units	86,190		129,024		65,752		61,122
Market performance-based awards	618,078		272,262		483,538		109,301
Weighted average units outstanding—diluted	139,192,198		138,762,045		139,050,965		135,598,696
Income per unit:
Basic	$	0.28	$	0.81	$	1.89	$	1.39
Diluted	$	0.27	$	0.80	$	1.88	$	1.39

We have excluded the following potentially dilutive securities in the calculations above as they would be antidilutive or not dilutive:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2015	2014	2015	2014
Potentially dilutive 2029 Debentures	—	1,121,910	—	3,948,379
Potentially dilutive Series E Cumulative Redeemable Preferred Units	4,567,661	5,060,744	4,440,429	5,367,507
Potentially dilutive Series F Cumulative Redeemable Preferred Units	2,896,800	3,209,512	2,816,110	3,404,060
Potentially dilutive Series G Cumulative Redeemable Preferred Units	3,960,900	4,388,483	3,850,569	4,654,496
Potentially dilutive Series H Cumulative Redeemable Preferred Units	5,804,286	6,437,332	5,642,608	3,449,841
Units subject to Forward Equity Offering	10,500,000	—	10,500,000	—
	27,729,647	20,217,981	27,249,716	20,824,283