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STOCK-BASED COMPENSATION - Employee Stock Purchase Plan (Detail) (Employee Stock Purchase Plan [Member])
6 Months Ended 12 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2012
Dec. 31, 2011
Employee Stock Purchase Plan [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected term (years) 6 months 6 months 6 months 6 months
Volatility 53.00% 43.00% 46.00% 46.00%
Risk-free interest rate 0.20% 0.20% 0.20% 0.10%
Expected dividends 0.00% 0.00% 0.00% 0.00%