Weighted Average Assumptions used in Determining Fair Value for Options Granted (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Schedule Of Weighted Average Assumptions For Fair Values Of Stock Options [Line Items]
Expected dividend yield	1.41%
Expected stock volatility	41.15%
Risk-free interest rate	2.30%
Expected holding period	7 years 2 months 12 days
Grant date fair value	$ 31.53