Quarterly report pursuant to Section 13 or 15(d)

Net Income Per Share (Details)

v3.7.0.1
Net Income Per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Earnings Per Share, Basic, Two Class Method [Abstract]    
Net income and comprehensive income $ 14,243 $ 13,099
Income allocated to participating securities (119) (64)
Numerator for basic and diluted income per share - net income $ 14,124 $ 13,035
Denominator for basic income per share - weighted-average shares 29,998 30,420
Denominator for diluted income per share - adjusted weighted-average shares 30,106 30,625
Basic income per share (dollars per share) $ 0.47 $ 0.43
Diluted income per share (dollars per share) $ 0.47 $ 0.43
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation 297 392
Equity Option [Member]    
Earnings Per Share, Basic, Two Class Method [Abstract]    
Effect of dilutive stock options and non-vested shares 75 165
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation 282 275
Key Employee Performance Share Based Plan [Member]    
Earnings Per Share, Basic, Two Class Method [Abstract]    
Effect of dilutive stock options and non-vested shares 33 40
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation 15 44
Nonvested Shares and Deferred Stock Units [Member]    
Earnings Per Share, Basic, Two Class Method [Abstract]    
Total number anti-dilutive options, non-vested shares, and performance shares excluded from income per diluted share computation   73