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	Dec. 31, 2014
Income Tax Contingency [Line Items]
Effective tax rate attributable to continuing operations	24.30%	32.20%	30.10%	32.90%
Increase in unrecognized tax benefits			$ 4.9
Gross accrued interest and penalties on unrecognized tax benefits	$ 0.7		0.7		$ 0.3
Unrecognized income tax benefits that, if recognized, would affect the effective tax rates	11.6		11.6		6.5
Unrecognized income tax benefits that, if recognized, would affect the effective tax rates , interest and penalties	$ 0.5		$ 0.5		$ 0.2