Earnings Per Common Share - Historical Net Income and Weighted Average Number of Shares of Common Stock Outstanding (Detail) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Weighted average number of shares of common stock outstanding	23,483	23,418	23,463	23,410
Shares assumed issued (less shares assumed purchased for treasury) for stock-based compensation	220	216	314	146
Outstanding shares for diluted earnings per share calculation	23,703	23,634	23,777	23,556