Earnings Per Share

9 Months Ended

Sep. 30, 2011

Earnings Per Share [Abstract]

Earnings Per Share

(6) The following table reconciles the numerators and denominators used in the calculation of basic and diluted earnings per share (EPS):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2011		2010		2011		2010
Numerators:
Numerator for both basic and diluted EPS, net income	$	43,397,064	$	34,291,244	$	124,202,115	$	100,810,704
Denominators:
Denominator for basic EPS, weighted-average shares outstanding		142,681,780		139,507,360		142,276,965		138,973,832
Potentially dilutive shares resulting from stock plans		1,633,240		1,051,833		1,859,434		1,192,643
Denominator for diluted EPS		144,315,020		140,559,193		144,136,399		140,166,475
Shares related to stock plans not included in diluted average common shares outstanding because their effect would be antidilutive		1,716,832		1,591,642		1,097,397		1,787,200