Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of calculation of basic and diluted earnings per share

The following table sets forth the computation of basic and diluted earnings per share for the three and six months ended June 30, 2012 and 2013.

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2013		2012		2013
Net income	$	10,296	$	9,533	$	20,264	$	20,025
Basic – weighted average shares outstanding	28,327		27,591		28,178		27,860
Effect of dilutive potential securities	345		392		399		398
Diluted – weighted average shares outstanding	28,672		27,983		28,577		28,258
Net income
Basic (per share)	$0.36		$0.35		$0.72		$0.72
Diluted (per share)	$0.36		$0.34		$0.71		$0.71