Quarterly report pursuant to Section 13 or 15(d)

Net Income Per Share (Details)

v2.4.0.8
Net Income Per Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Numerator [Abstract]        
Numerator for basic and diluted income per share - net income $ 16,744 $ 14,197 $ 44,123 $ 38,882
Denominator [Abstract]        
Denominator for basic income per share - weighted-average shares 30,415 30,374 30,710 30,017
Denominator for diluted income per share - adjusted weighted-average shares 30,932 30,986 31,234 30,677
Basic income per share (dollars per share) $ 0.55 $ 0.47 $ 1.44 $ 1.30
Diluted income per share (dollars per share) $ 0.54 $ 0.46 $ 1.41 $ 1.27
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation     108 186
Stock Option [Member]
        
Denominator [Abstract]        
Effect of dilutive stock options and non-vested shares 418 447 431 512
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation     108 186
Key Employee Performance Share Based Plan [Member]
        
Denominator [Abstract]        
Effect of dilutive stock options and non-vested shares 37 13 41 9
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation     0 0
Nonvested Shares [Member]
        
Denominator [Abstract]        
Effect of dilutive stock options and non-vested shares 62 152 52 139