XML 25 R47.htm IDEA: XBRL DOCUMENT v2.4.0.6
Income Taxes (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Income Tax Contingency [Line Items]        
U.S. federal tax statutory rate 38.50% 37.00% 37.60% 37.20%