v2.4.0.8
Equity Incentive Plans - Additional Information (Details) (USD $)
3 Months Ended 9 Months Ended 12 Months Ended 2 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2011
Shares Available For Grant
Sep. 30, 2013
Shares Available For Grant
Dec. 31, 2012
Shares Available For Grant
Dec. 31, 2010
Shares Available For Grant
Dec. 31, 2009
Shares Available For Grant
Mar. 01, 2013
RSUs
Sep. 30, 2013
RSUs
Sep. 30, 2012
RSUs
Sep. 30, 2013
RSUs
Sep. 30, 2012
RSUs
Dec. 31, 2012
RSUs
Dec. 31, 2011
RSUs
Sep. 30, 2013
Stock Options
Sep. 30, 2012
Stock Options
Sep. 30, 2013
Stock Options
Sep. 30, 2012
Stock Options
Dec. 31, 2012
Stock Options
Dec. 31, 2011
Stock Options
Dec. 31, 2010
Stock Options
Sep. 30, 2013
Restricted Stock
Sep. 30, 2012
Restricted Stock
Sep. 30, 2013
Restricted Stock
Sep. 30, 2012
Restricted Stock
Dec. 31, 2012
Restricted Stock
Dec. 31, 2011
Restricted Stock
Dec. 31, 2010
Restricted Stock
Sep. 30, 2013
Replacement Performance Shares
Sep. 30, 2013
New Performance Shares
Sep. 30, 2013
Performance Shares
Sep. 30, 2013
Performance Shares
Dec. 31, 2012
1998 Equity Incentive Plan
Dec. 31, 2011
1998 Equity Incentive Plan
Dec. 31, 2012
Common Stock
Sep. 30, 2013
Maximum
RSUs
Sep. 30, 2013
Maximum
Stock Options
Sep. 30, 2013
Maximum
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award                                                                                      
Increase in shares available for issuance under the Equity Incentive Plan               12,800,000                                                           1,088,834 12,800,000        
Total shares approved under the Equity Incentive Plan                                                                           69,900,000          
Shares available for issuance under the Equity Incentive Plan               15,752,370 13,896,794 14,643,932 4,280,180 7,285,606                                                              
Vesting period                                   5 years           5 years             5 years     6 months 6 months           5 years 5 years 5 years
Number of shares that RSUs convert into on the applicable vesting date                               1   1                                                  
Stock options expiration period                                           10 years   10 years                                      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period                               97,254   119,422 44,904                             671,400                  
Exercise price adjustment resulting from stock split                                               50.00%                                      
RSUs granted (shares)                         594,700     924,312   1,504,410 1,643,348                             671,400 275,400   946,800            
Performance Period (Duration)                                                                         5 years            
Closing stock price                                                                               $ 21.10      
Outstanding RSUs or restricted stock, intrinsic value                                   $ 49,600,000                         $ 2,400,000                        
Outstanding stock options, intrinsic value                                               132,800,000                                      
Exercisable stock options, intrinsic value                                               102,300,000                                      
Forfeiture rates used for grants to employees                               10.00%   10.00%               9.00%                                  
Forfeiture rates used for grants to non-employee directors and executive officers                               0.00%   0.00%               0.00%                                  
Fair value of RSUs or restricted stock vested during the period                               14,300,000   7,800,000 2,200,000                       1,600,000 1,100,000 1,000,000                    
Period of time as a public company             6 years                                                                        
Number of coupon issues related to the risk-free rate                                                   0                                  
Dividend Yield             0.00%                                                                        
Fair value of stock options vested                                               7,200,000 8,600,000 7,700,000                                  
Intrinsic value of stock options exercised                                               45,300,000 24,800,000 43,200,000                                  
Stock-based compensation expense 5,730,000 3,998,000 16,292,000 11,976,000 15,634,000 13,107,000 9,974,000             4,559,000 2,048,000 12,674,000 6,131,000 8,411,000 3,666,000 1,124,000 1,720,000 3,457,000 5,162,000 6,310,000 8,129,000 8,771,000 47,000 230,000 161,000 683,000 913,000 913,000 913,000     2,300,000 6,000,000            
Unrecognized Stock Based Compensation Expense Expected To Be Recognize In Current Year $ 5,629,000   $ 5,629,000                     $ 4,459,000   $ 4,459,000       $ 1,123,000   $ 1,123,000         $ 47,000   $ 47,000             $ 2,300,000 $ 2,300,000