v2.4.0.6
Earnings Per Share (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Numerator:                      
Net income (loss) $ 5,520 $ 5,527 $ 2,370 $ 6,694 $ 16,295 $ 13,721 $ 9,461 $ 10,654 $ 19,811 $ 50,131 $ 15,290
Denominator:                      
Denominator for basic earnings per share - weighted average shares                 21,680 23,300 23,184
Effect of dilutive securities:                      
Employee stock options                 52 110 158
Denominator for diluted earnings per share - weighted average shares                 21,732 23,410 23,342