v2.4.0.6
Reconciliation of Statutory Federal Income Tax Rate to Effective Tax Rate (Parenthetical) (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Income Taxes [Line Items]        
Federal statutory rate 35.00% 35.00% 35.00% 35.00%