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


	Three months ended September 30,						Nine months ended September 30,
	2011			2010			2011			2010
Numerator for basic and diluted earnings per share:
Net income	$	36,911		$	20,175		$	97,019		$	57,901
Effect of reallocating undistributed earnings of participating securities		(212	)		(123	)		(562	)		(361	)

Net income available under the two-class method	$	36,699		$	20,052		$	96,457		$	57,540

Denominator:
Denominator for basic earnings per share— weighted-average shares		23,026,741			22,966,617			23,022,836			22,968,492
Effect of dilutive securities:
Employee stock options (See Note 6)		1,351			2,936			1,333			4,055
Deferred stock awards (See Note 6)		—			4,039			—			4,028

Dilutive potential common shares		1,351			6,975			1,333			8,083

Denominator for diluted earnings per share— adjusted weighted-average shares		23,028,092			22,973,592			23,024,169			22,976,575

Basic earnings per share	$	1.59		$	0.87		$	4.19		$	2.51

Diluted earnings per share	$	1.59		$	0.87		$	4.19		$	2.50