Earnings per Share

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

Earnings per Share

Earnings per Share

The Company has unvested shares of restricted stock outstanding that are considered participating securities and, therefore, computes basic and diluted earnings per share under the two-class method. Basic earnings per share for the periods are based upon the weighted average number of shares of common stock outstanding during the periods. Diluted earnings per share include the effect of certain stock options.

	Three Months Ended September 30,						Nine Months Ended September 30,
	2012			2011			2012			2011
Net income	$	86,964		$	67,930		$	290,278		$	232,523
Less:
Net income attributable to participating securities	(452		)	(598		)	(1,682		)	(2,087		)
Net income attributable to common shareholders	$	86,512		$	67,332		$	288,596		$	230,436

The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2012		2011		2012		2011
Weighted average common shares—basic	66,311,958		66,012,102		66,240,225		65,919,892
Plus incremental shares from:
Assumed exercise of options	344,802		369,830		381,295		387,712
Weighted average common shares—diluted	66,656,760		66,381,932		66,621,520		66,307,604
Earnings per share:
Basic	$	1.30	$	1.02	$	4.36	$	3.50
Diluted	$	1.30	$	1.01	$	4.33	$	3.48

Excluded from the computation of diluted earnings per share are options to purchase 168,362 and 99,592 shares of common stock for the three months ended September 30, 2012 and 2011, respectively, and 293,062 and 151,923 shares of common stock for the nine months ended September 30, 2012 and 2011, respectively. These options were outstanding during the periods reported but were excluded because the option exercise price was greater than the average market price of the shares.