Reconciliation of Weighted Average Shares for Basic and Diluted Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Weighted average shares for basic earnings per share	25,463,994	25,137,531	25,452,991	25,126,684
Weighted average shares for diluted earnings per share	25,704,931	25,334,716	25,684,931	25,323,187
Restricted Stock
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock and options	138,261	89,114	128,942	88,710
Stock Options
Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Line Items]
Non-vested restricted stock and options	102,676	108,071	102,998	107,793