Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stock Option Activity (Detail)

v2.4.0.8
Stock-Based Compensation - Stock Option Activity (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
9 Months Ended 12 Months Ended
Sep. 30, 2014
Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Number of Shares Underlying Options, Outstanding at beginning of period 4,927,000  
Number of Shares Underlying Options, Granted 1,118,000  
Number of Shares Underlying Options, Exercised (1,110,000)  
Number of Shares Underlying Options, Forfeited (33,000)  
Number of Shares Underlying Options, Outstanding at end of period 4,902,000 4,927,000
Vested and expected to vest - end of period 4,853,000  
Weighted Average Exercise Price Per Share, Outstanding at beginning of period $ 6.95  
Weighted Average Exercise Price Per Share, Granted $ 7.05  
Weighted Average Exercise Price Per Share, Exercised $ 5.06  
Weighted Average Exercise Price Per Share, Forfeited $ 8.43  
Weighted Average Exercise Price Per Share, Outstanding at end of period $ 7.40 $ 6.95
Vested and expected to vest - end of period $ 7.40  
Weighted Average Remaining Contractual Term, Outstanding balance 2 years 10 months 21 days 2 years 10 months 6 days
Weighted Average Remaining Contractual Term, Granted 4 years 5 months 5 days  
Weighted Average Remaining Contractual Term, Exercised 11 months 12 days  
Weighted Average Remaining Contractual Term, Forfeited 2 years 6 months 18 days  
Vested and expected to vest - end of period 2 years 10 months 21 days  
Aggregate Intrinsic Value, Outstanding at beginning of period $ 2.81  
Aggregate Intrinsic Value, Outstanding at end of period 2.31 2.81
Vested and expected to vest - end of period $ 2.29