The following table sets forth the computation of basic and diluted earnings per share under the two-class method:


	Three months ended
	March 31,
	2012			2011
Numerator for basic and diluted earnings per share:
Net income	$	30,291		$	30,164
Effect of reallocating undistributed earnings of participating securities		(165	)		(176	)

Net income available under the two-class method	$	30,126		$	29,988

Denominator:
Denominator for basic earnings per share— weighted-average shares		22,973,986			23,014,530
Effect of dilutive securities:
Employee stock options (See Note 5)		1,280			1,302

Dilutive potential common shares		1,280			1,302

Denominator for diluted earnings per share— adjusted weighted-average shares		22,975,266			23,015,832

Basic earnings per share	$	1.31		$	1.30

Diluted earnings per share	$	1.31		$	1.30