Earnings (Loss) Per Share (Tables)

12 Months Ended

Dec. 31, 2012

Earnings (Loss) Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The computations of basic and diluted income per share for the years ended December 31, 2010, 2011, and 2012 are as follows:

	December 31,
	2010		2011		2012
Numerator:
Net income	$	27,015	$	25,226	$	43,865
Denominator:
Basic earnings per share - weighted average shares outstanding	31,286		31,744		32,226
Effect of potential diluted securities:
Employee stock options and restricted stock units - dilutive shares	206		512		627
Diluted earnings per share - weighted average shares outstanding	31,492		32,256		32,853
Earnings per share:
Basic	$	0.86	$	0.79	$	1.36
Diluted	$	0.86	$	0.78	$	1.34