Earning 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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Weighted average number of shares of common stock outstanding	23,414	23,390	23,406	24,405
Shares assumed issued (less shares assumed purchased for treasury) for stock-based compensation	136	139	110	178
Outstanding shares for diluted earnings per share calculation	23,550	23,529	23,516	24,583