Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Detail)

v2.4.0.8
Income Taxes - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
IncomeTaxesLineItems [Line Items]    
Gross unrecognized tax benefit balance, change within the next twelve months, lower limit $ 0  
Gross unrecognized tax benefit balance, change within the next twelve months, upper limit $ 7.6  
Effective income tax rate 35.90% 34.90%