Consolidated Statements of Stockholders' Equity - USD ($)
$ in Thousands
Total
Class A common stock
Class B common stock
Class U common stock
Common Stock
Class A common stock
Common Stock
Class B common stock
Common Stock
Class U common stock
Treasury Stock
Additional Paid-in Capital
Accumulated Deficit
Accumulated Other Comprehensive Income (Loss)
Balance, Beginning at Dec. 31, 2013 $ 136,024       $ 6 $ 2 $ 1   $ 927,377 $ (791,596) $ 234
Balance, Beginning, Shares at Dec. 31, 2013         59,793,603 18,969,222 9,352,729        
Issuance of common stock upon exercise of stock options or awards of restricted stock units $ 1,841               1,841    
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares 1,042,000       1,531,100            
Stock-based compensation expense $ 4,351               4,351    
Class B common stock exchanged for Class A common stock         39,187 (39,187)          
Repurchase of Class A common stock (12,543)               (12,543)    
Repurchase of Class A common stock, Shares               (2,469,920)      
Retirement of treasury stock, Shares         (2,469,920)     2,469,920      
Dividends paid (8,865)               (8,865)    
Change in fair value of interest rate swap agreements (2,372)                   (2,372)
Net income 27,122                 27,122  
Balance, Ending at Dec. 31, 2014 145,558       $ 6 $ 2 $ 1   912,161 (764,474) (2,138)
Balance, Ending, Shares at Dec. 31, 2014         58,893,970 18,930,035 9,352,729        
Issuance of common stock upon exercise of stock options or awards of restricted stock units $ 2,177               2,177    
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares 966,000       1,580,779            
Stock-based compensation expense $ 5,240               5,240    
Class B common stock exchanged for Class A common stock         4,002,422 (4,002,422)          
Dividends paid (9,350)               (9,350)    
Change in fair value of interest rate swap agreements (1,977)                   (1,977)
Net income 25,625                 25,625  
Balance, Ending at Dec. 31, 2015 167,273       $ 6 $ 2 $ 1   910,228 (738,849) (4,115)
Balance, Ending, Shares at Dec. 31, 2015   64,477,171 14,927,613 9,352,729 64,477,171 14,927,613 9,352,729        
Issuance of common stock upon exercise of stock options or awards of restricted stock units $ 781       $ 1       780    
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares 925,000       1,409,085            
Stock-based compensation expense $ 5,035               5,035    
Repurchase of Class A common stock, Shares   0                  
Dividends paid (11,176)               (11,176)    
Change in fair value of interest rate swap agreements 1,138                   1,138
Net income 20,405                 20,405  
Balance, Ending at Dec. 31, 2016 $ 183,456       $ 7 $ 2 $ 1   $ 904,867 $ (718,444) $ (2,977)
Balance, Ending, Shares at Dec. 31, 2016   65,886,256 14,927,613 9,352,729 65,886,256 14,927,613 9,352,729