v2.4.0.6
Reconciliation of Differences Between Statutory Tax Rate and Effective Tax Rate for CIT (Parenthetical) (Detail)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Reconciliation of Provision of Income Taxes [Line Items]      
Corporate Income Tax (CIT) statutory rate 25.00% 25.00% 25.00%
Percentage tax reduction for qualified research and development expenses 50.00% 50.00% 50.00%