v2.4.0.6
Share-Based Compensation - Summary of Stock Options Outstanding and Activity (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Share Based Compensation Arrangements By Share Based Payment Award Options [Line Items]      
Outstanding, Aggregate Intrinsic Value, Beginning Value $ 6,315 $ 4,567   
Share Subject to Stock Options, Beginning Balance 260,097 334,338 409,327
Outstanding, Aggregate Intrinsic Value, Ending Balance 547 6,315 4,567
Weighted Average Remaining Contractual Term, Outstanding, Beginning Balance 1 year 11 months 9 days 3 years 10 months 6 days 5 years 4 months 28 days
Outstanding, Exercisable, Aggregate Intrinsic Value $ 547    
Weighted Average Remaining Contractual Term, Outstanding, Ending Balance 4 years 10 months 17 days 1 year 11 months 9 days 3 years 10 months 6 days
Weighted Average Exercise Price, Outstanding, Beginning Balance $ 5.13 $ 7.01 $ 8.03
Weighted Average Remaining Contractual Term, Exercisable, Ending Balance 4 years 10 months 17 days    
Weighted Average Exercise Price, Outstanding, Granted         
Weighted Average Exercise Price, Outstanding, Exercised $ 3.68 $ 13.59 $ 12.76
Weighted Average Exercise Price, Outstanding, Canceled     $ 12.00
Weighted Average Exercise Price, Outstanding, Ending Balance $ 12.38 $ 5.13 $ 7.01
Weighted Average Exercise Price, Exercisable, Ending Balance $ 12.38    
Share Subject to Stock Options, Granted         
Shares Subject to Stock Options, Exercised (216,822) (74,241) (58,798)
Shares Subject to Stock Options, Canceled     (16,191)
Share Subject to Stock Options, Ending Balance 43,275 260,097 334,338
Shares Subject to Stock Options, Shares Exercisable, Ending Balance 43,275