XML 20 R31.htm IDEA: XBRL DOCUMENT v2.4.0.8
Stock-Based Compensation (Details 3) (USD $)
 3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 0 Months Ended 1 Months Ended
Sep. 30, 2013
Options
Sep. 30, 2012
Options
Sep. 30, 2013
Options
Sep. 30, 2012
Options
Sep. 30, 2013
Options
Minimum
Sep. 30, 2013
Options
Minimum
Sep. 30, 2013
Options
Maximum
Sep. 30, 2013
Options
Maximum
Aug. 30, 2013
ESPP
Feb. 28, 2013
ESPP
Jun. 30, 2010
ESPP
Period
Sep. 30, 2013
ESPP
Stock-Based Compensation                        
Outstanding options fully vested and expected to vest (in shares) 9,900,000   9,900,000                  
Remaining contractual life of options fully vested and expected to vest     3 years 7 months 17 days                  
Weighted average exercise price of options fully vested and expected to vest (in dollars per share) $ 4.06   $ 4.06                  
Aggregate intrinsic value of options fully vested and expected to vest (in dollars) $ 3,500,000   $ 3,500,000                  
Fair value of shares vested (in dollars)     2,500,000 1,700,000                
Total intrinsic value of awards exercised (in dollars)     800,000 2,300,000                
Awards exercisable (in shares)   6,200,000   6,200,000                
Weighted average exercise price of awards exercisable (in dollars per share)   $ 4.43   $ 4.43                
Assumptions used in estimation of fair value of the share-based payment awards on the grant date                        
Risk-free interest rate, minimum (as a percent) 1.00% 0.20% 0.50% 0.20%                
Risk-free interest rate, maximum (as a percent) 1.70% 0.60% 1.70% 0.80%                
Volatility, minimum (as a percent) 57.70% 65.20% 57.70% 65.20%                
Volatility, maximum (as a percent) 62.90% 73.10% 62.90% 73.10%                
Expected life   4 years   4 years 4 years 4 years 5 years 5 years        
Dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%                
Employee Stock Purchase Plan                        
Number of shares reserved for issuance                     2,000,000  
Maximum amount of shares that eligible employee may purchase annually (in dollars)                     25,000  
Number of offering periods                     2  
Offering period                     6 months  
Purchase price to be paid by participants as a percentage of price per share either at the beginning or the end of each six-month offering period, whichever is less                     85.00%  
Shares of common stock issued under the plan                 128,000 147,000    
Aggregate purchase price (in dollars)                 $ 381,000 $ 426,000    
Shares authorized and unissued                       1,061,000