Quarterly report pursuant to Section 13 or 15(d)

Accounting for Uncertainty in Income Taxes - Additional Information (Detail)

v2.4.0.8
Accounting for Uncertainty in Income Taxes - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
9 Months Ended 12 Months Ended
Sep. 30, 2013
Dec. 31, 2012
Sep. 30, 2012
Income Tax Disclosure [Abstract]      
Liability for unrecognized tax $ 10.5   $ 12.0
Unrecognized tax favorable impact on effective tax rate 3.8   5.2
Accrued interest and penalties applied to uncertain tax positions $ 7.7 $ 7.0