v2.4.0.8
Income Taxes - Additional Information (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Income Tax Disclosure [Abstract]        
Effective income tax rate 35.30% 34.70% 35.10% 36.30%