Earnings Per Share - Weighted-Average Number of Shares of Common Stock Used to Calculate Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Weighted-average number of shares of common stock for calculating basic earnings per share	23,911	25,334	23,891	25,853
Effect of potentially dilutive securities from equity-based compensation	130	74	66	101
Weighted-average number of shares of common stock for calculating diluted earnings per share	24,041	25,408	23,957	25,954