We determine basic earnings per share based on the weighted average number of shares of common stock outstanding during the period and we consider any participating securities for purposes of applying the two-class method. We determine diluted earnings per share based on the weighted average number of shares of common stock outstanding combined with the incremental weighted average shares that would have been outstanding assuming all potentially dilutive common shares were converted into shares at the earliest date possible. The following table sets forth the computation of our basic and diluted earnings per share.

	For the Three Months Ended June 30,				For the Six Months Ended June 30,

	*2012*		*2011*		*2012*		*2011*
Net Income available to Common Stockholders — Basic	$	215,445	$	205,121	$	860,855	$	384,532
Effect of dilutive securities:
Impact to General Partner's interest in Operating Partnership from all dilutive securities and options		—		51		—		29

Net Income available to Common Stockholders — Diluted	$	215,445	$	205,172	$	860,855	$	384,561

Weighted Average Shares Outstanding — Basic		303,252,359		293,367,771		299,472,884		293,224,782
Effect of stock options		1,042		34,582		1,079		127,905

Weighted Average Shares Outstanding — Diluted		303,253,401		293,402,353		299,473,963		293,352,687

For the six months ended June 30, 2012, potentially dilutive securities include stock options, units that are exchangeable for common stock and long-term incentive performance, or LTIP, units granted under our long-term incentive performance programs that are convertible into units and exchangeable for common stock. The only securities that had a dilutive effect for the six months ended June 30, 2012 and 2011 were stock options. We accrue dividends when they are declared.