Consolidated Statements of Stockholders' Equity (USD $)
Total
USD ($)
Class A
Class B
USD ($)
Class A common stock
Class A
USD ($)
Class A common stock
Class B
USD ($)
Treasury stock
USD ($)
Additional paid-in capital
USD ($)
Accumulated deficit
USD ($)
Beginning Balance at Dec. 31, 2011 $ 159,008,000     $ 99,000 $ 281,000 $ (1,067,000) $ 297,465,000 $ (137,770,000)
Beginning Balance, share at Dec. 31, 2011           (157,000)    
Beginning Balance (in shares) at Dec. 31, 2011       9,632,000 28,074,000      
Issuance of common stock upon exercise of stock options (in shares)         6,000      
Issuance of common stock upon exercise of stock options 27,000           27,000  
Income tax shortfall of option exercises and restricted stock vesting, net (4,006,000)           (4,006,000)  
Issuance of common stock under employee stock purchase plan (in shares)         10,000      
Issuance of common stock under employee stock purchase plan 36,000           36,000  
Issuance of restricted stock (in shares)         1,484,000      
Issuance of restricted stock 15,000       15,000      
Tax withholding related to restricted stock awards, Shares         (7,000) (384,000)    
Tax withholding related to restricted stock awards (1,611,000)         (4,000) (1,607,000)  
Repurchase of Class B common stock, shares     (387,000)     (387,000)    
Repurchase of Class B common stock (1,651,000)   (1,700,000)     (1,651,000)    
Conversion of Class A common stock to Class B common stock (in shares)       (62,000) 62,000      
Conversion of Class A common stock to Class B common stock       (1,000) 1,000      
Repurchase of unvested restricted stock, shares           (723,000)    
Repurchase of unvested restricted stock (7,000)         (7,000)    
Stock compensation from options and restricted stock, net of estimated forfeitures 15,696,000           15,696,000  
Retirement of treasury stock (in shares)         (1,249,000) 1,249,000    
Retirement of treasury stock         (13,000) 2,716,000 (2,703,000)  
Net income (loss) (35,196,000)             (35,196,000)
Common stock cash dividends (9,376,000)           (9,376,000)  
Ending Balance at Dec. 31, 2012 122,935,000     98,000 284,000 (13,000) 295,532,000 (172,966,000)
Ending Balance, share at Dec. 31, 2012           (402,000)    
Ending Balance (in shares) at Dec. 31, 2012       9,570,000 28,380,000      
Issuance of common stock upon exercise of stock options (in shares)         560,000      
Issuance of common stock upon exercise of stock options 2,931,000       6,000   2,925,000  
Issuance of common stock upon vesting of restricted stock units         71,000      
Income tax shortfall of option exercises and restricted stock vesting, net (384,000)           (384,000)  
Issuance of common stock under employee stock purchase plan (in shares)         12,000      
Issuance of common stock under employee stock purchase plan 72,000           72,000  
Issuance of restricted stock (in shares)         735,000      
Issuance of restricted stock 7,000       7,000      
Tax withholding related to restricted stock awards, Shares           (220,000)    
Tax withholding related to restricted stock awards (1,766,000)         (2,000) (1,764,000)  
Repurchase of Class B common stock, shares     (31,000)     (31,000)    
Repurchase of Class B common stock (119,000)   (119,000)     (119,000)    
Conversion of Class A common stock to Class B common stock (in shares)       (1,800,000) 1,800,000      
Conversion of Class A common stock to Class B common stock       (18,000) 18,000      
Repurchase of unvested restricted stock, shares           (185,000)    
Repurchase of unvested restricted stock (2,000)         (2,000)    
Stock compensation from options and restricted stock, net of estimated forfeitures 9,264,000           9,264,000  
Retirement of treasury stock (in shares)     679,000   (679,000) 679,000    
Retirement of treasury stock         (6,000) 134,000 (128,000)  
Net income (loss) 1,817,000             1,817,000
Ending Balance at Dec. 31, 2013 134,755,000     80,000 309,000 (2,000) 305,517,000 (171,149,000)
Ending Balance, share at Dec. 31, 2013     (159,000)     (159,000)    
Ending Balance (in shares) at Dec. 31, 2013   7,770,000 30,720,000 7,770,000 30,879,000      
Issuance of common stock in offering, net of costs (in shares)         3,371,000      
Issuance of common stock in offering, net of costs 32,482,000       34,000   32,448,000  
Issuance of common stock upon exercise of stock options (in shares) 747,899       748,000      
Issuance of common stock upon exercise of stock options 4,177,000       7,000   4,170,000  
Issuance of common stock upon vesting of restricted stock units         257,000      
Issuance of common stock upon vesting of restricted stock units shares 3,000       3,000      
Income tax shortfall of option exercises and restricted stock vesting, net (1,229,000)           (1,229,000)  
Issuance of common stock under employee stock purchase plan (in shares)         12,000      
Issuance of common stock under employee stock purchase plan 67,000           67,000  
Issuance of restricted stock (in shares)         65,000      
Issuance of restricted stock 1,000       1,000      
Tax withholding related to restricted stock awards, Shares           (175,000)    
Tax withholding related to restricted stock awards (1,080,000)         (1,000) (1,079,000)  
Repurchase of Class B common stock, shares     (669,000)     (669,000)    
Repurchase of Class B common stock (2,505,000)   (2,500,000)     (2,505,000)    
Conversion of Class A common stock to Class B common stock (in shares)       (2,537,000) 2,537,000      
Conversion of Class A common stock to Class B common stock       (25,000) 25,000      
Repurchase of unvested restricted stock, shares           (49,000)    
Repurchase of unvested restricted stock (1,000)         (1,000)    
Stock compensation from options and restricted stock, net of estimated forfeitures 11,903,000           11,903,000  
Retirement of treasury stock (in shares)     598,000   (598,000) 598,000    
Retirement of treasury stock         (6,000) 6,000    
Net income (loss) (19,090,000)             (19,090,000)
Common stock cash dividends (3,330,000)           (3,330,000)  
Ending Balance at Dec. 31, 2014 $ 156,153,000     $ 55,000 $ 373,000 $ (2,503,000) $ 348,467,000 $ (190,239,000)
Ending Balance, share at Dec. 31, 2014     (454,000)     (454,000)    
Ending Balance (in shares) at Dec. 31, 2014   5,233,000 36,817,000 5,233,000 37,271,000