Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective tax rate for income from continuing operations	30.20%	37.50%	36.30%	35.10%
Effective income tax rate reconciliation, deduction, employee benefit plan settlement expense, percent	3.50%
Recognized Discrete Tax Benefits	$ (1.0)	$ 0.5	$ (1.0)	$ 0.5