Income Per Unit

9 Months Ended

Sep. 30, 2011

Income Per Unit [Abstract]

Income Per Unit

8. 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,
	2011		2010		2011		2010
Net income available to common unitholders	$	33,329	$	10,176	$	99,533	$	35,544
Weighted average units outstanding—basic		105,069,280		92,815,152		100,845,740		87,138,978
Potentially dilutive common units:
Stock options		197,632		228,135		192,885		206,039
Class C Units (2007 Grant)		49,163		139,386		38,654		122,590
Unvested incentive units		162,832		213,130		145,032		176,247
Series E preferred units		914,480		—		308,176		—
Excess exchange value of the 2026 Debentures		—		1,647,308		494,292		1,521,201
Weighted average units outstanding—diluted		106,393,387		95,043,111		102,024,779		89,165,055
Income per unit:
Basic	$	0.32	$	0.11	$	0.99	$	0.41
Diluted	$	0.31	$	0.11	$	0.97	$	0.40

On or after July 15, 2026, the 2026 Debentures would have been exchangeable at the then-applicable exchange rate for cash (up to the principal amount of the 2026 Debentures) and, with respect to any excess exchange value, into cash, shares of Digital Realty Trust, Inc. common stock or a combination of cash and shares of Digital Realty Trust, Inc. common stock. Pursuant to the terms of the Operating Partnership's agreement of limited partnership, the Operating Partnership would have delivered to Digital Realty Trust, Inc. one common unit for each share of common stock issuable upon exchange of the 2026 Debentures. The 2026 Debentures also would have been exchangeable prior to July 15, 2026, but only upon the occurrence of certain specified events, including if the weighted average common stock price exceeded a specified strike price as of the end of a fiscal quarter. During the three months ended September 30, 2011, the remaining 2026 Debentures were redeemed and exchanged. Using the treasury method, 494,292 common units contingently issuable upon settlement of the excess exchange value were included as potentially dilutive common units in determining diluted earnings per unit for the nine months ended September 30, 2011. During the three and nine months ended September 30, 2010, the weighted average common stock price exceeded the strike price as of September 30, 2010 of $31.84. Therefore, using the treasury method, 1,647,308 and 1,521,201 common units contingently issuable upon settlement of the excess exchange value were included as potentially dilutive common units in determining diluted earnings per unit for the three and nine months ended September 30, 2010, respectively.

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,
	2011		2010		2011		2010
Potentially dilutive 2029 Debentures		6,368,292		6,209,949		6,309,599		6,200,267
Potentially dilutive Series C Cumulative Convertible Preferred Units		2,783,811		3,666,380		3,097,084		3,660,478
Potentially dilutive Series D Cumulative Convertible Preferred Units		5,603,998		8,316,008		6,775,337		8,256,625
		14,756,101		18,192,337		16,182,020		18,117,370