Employee Benefits - Summary of Stock Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	$ 2,635	$ 2,099	$ 8,050	$ 6,441
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	60	97	221	280
Selling [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	45	48	154	149
Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense	$ 2,530	$ 1,954	$ 7,675	$ 6,012