Basic and Diluted Weighted Average Shares Outstanding (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Weighted Average Number of Shares Outstanding [Line Items]
Weighted average common shares	32,925,004	32,677,003	32,860,382	32,292,588
Dilutive common stock options	764,556	650,374	757,617	807,011
Weighted average common shares, assuming dilution	33,689,560	33,327,377	33,617,999	33,099,599