Earnings Per Share - Number of Potential Common Shares that have been Excluded from Computation of Diluted Earnings Per Share for Indicated Period Due to Their Anti-Dilutive Nature (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]
Potential common shares	681	696	683	696