v2.4.0.8
Earnings per Common Share Diluted Earnings Per Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Diluted earnings per common share [Line Items]        
Net Income $ 11,304 $ 10,869 $ 26,891 $ 27,237
Diluted earnings per common share [Abstract]        
Income attributable to preferred stock (1,798) (1,756) (4,289) (4,406)
Common Class A [Member]
       
Diluted net income [Abstract]        
Net income allocated, basic 8,249 7,451 19,514 18,608
Re-Allocated Earnings 1,087 1,394 2,642 3,537
Diluted net income allocated to common stockholders 9,336 8,845 22,156 22,145
Diluted weighted-average shares issued and outstanding [Abstract]        
Weighted-average Class B shares issued and outstanding 31,463 29,098 31,208 28,968
Dilutive potential common shares [Abstract]        
Incremental Common Shares Attributable to Conversions of Other Classes of Common Stock 4,975 6,640 5,086 6,830
Diluted weighted-average shares issued and outstanding 36,686 35,746 36,458 35,810
Earnings Per Share, Basic, Undistributed $ 0.26 $ 0.26 $ 0.63 $ 0.64
Diluted earnings per common share [Abstract]        
Diluted Earnings Per Share $ 0.25 $ 0.25 $ 0.61 $ 0.62
Common Class B [Member]
       
Diluted net income [Abstract]        
Net income allocated, basic 1,027 1,324 2,505 3,340
Re-Allocated Earnings 239 319 586 883
Diluted net income allocated to common stockholders 1,266 1,643 3,091 4,223
Diluted weighted-average shares issued and outstanding [Abstract]        
Weighted-average Class B shares issued and outstanding 3,917 5,171 4,006 5,200
Dilutive potential common shares [Abstract]        
Diluted weighted-average shares issued and outstanding 4,975 6,640 5,086 6,830
Earnings Per Share, Basic, Undistributed $ 0.26 $ 0.26 $ 0.63 $ 0.64
Diluted earnings per common share [Abstract]        
Diluted Earnings Per Share $ 0.25 $ 0.25 $ 0.61 $ 0.62
Common Class A [Member] | Common Class B [Member]
       
Diluted earnings per common share [Abstract]        
Undistributed Earnings Allocated to Participating Securities $ 8,479 $ 7,789 $ 20,097 $ 19,491
Employee Stock [Member] | Common Class A [Member]
       
Dilutive potential common shares [Abstract]        
Incremental Common Shares Attributable to Share-based Payment Arrangements 2 5 0 7
Restricted Stock Units (RSUs) [Member] | Common Class A [Member]
       
Dilutive potential common shares [Abstract]        
Incremental Common Shares Attributable to Share-based Payment Arrangements 205 3 154 5
Employee Stock Option [Member] | Common Class A [Member]
       
Dilutive potential common shares [Abstract]        
Incremental Common Shares Attributable to Share-based Payment Arrangements 41 0 10 0
Employee Stock Option [Member] | Common Class B [Member]
       
Dilutive potential common shares [Abstract]        
Incremental Common Shares Attributable to Share-based Payment Arrangements 1,058 1,469 1,080 1,630