Earnings Per Share - Weighted Average Shares and Share Equivalents Used to Calculate Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Weighted average number of shares outstanding used to calculate basic EPS (in shares)	3,561	3,706	3,619	3,684
Dilutive securities:
Stock options and restricted share units (in shares)	281	233	274	212
Weighted average number of shares and share equivalents outstanding used to calculate diluted EPS (in shares)	3,842	3,939	3,893	3,896