Stock-Based Incentive Plan - Compensation Expense Related to Stock Incentive Plans Recognized (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Total expense	$ 1,183	$ 1,292
Tax benefit on nonqualified stock option expense, restricted stock awards and disqualifying dispositions of incentive stock options	243	284
Stock Options [Member]
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Total expense	190	378
Restricted Stock Awards and Restricted Stock Units [Member]
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Total expense	949	878
Employee Stock Purchase Plan [Member]
Share-based Payment Arrangement, Additional Disclosure [Abstract]
Total expense	$ 44	$ 36