Income Taxes - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
|
Income Tax Disclosure [Abstract] | ||||
Income taxes | $ 43.9 | $ (13.3) | $ 114.8 | $ 76.9 |
Effective income tax rate | 31.90% | 647.90% | 31.10% | 27.20% |
Utilization of deferred tax asset interest expense | $ (240.8) | |||
Total amount of unrecognized tax benefits, including related interest and penalties | 57.7 | $ 57.7 | ||
Unrecognized tax benefits excluding interest and penalties that if recognized would affect the effective tax rate | 45.5 | 45.5 | ||
Total accrued interest for tax contingencies | 7.0 | 7.0 | ||
Total accrued penalties for tax contingencies | 1.4 | 1.4 | ||
Amount of unrecognized tax benefits that could decrease within the next 12 months | 12.7 | 12.7 | ||
Decrease in unrecognized tax benefits due to the settlement of audits or resolution of administrative or judicial proceedings | 5.7 | 5.7 | ||
Decrease in unrecognized tax benefits expiration of statute of limitations | $ 7.0 | $ 7.0 |