Stock Incentive Plans - Summary of Expense Relating to Employee and Nonemployee Stock-Based Payment Awards from Stock Options and RSUs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	$ 10,639	$ 6,748	$ 26,583	$ 17,424
Cost of testing services
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	750	431	1,715	1,101
Cost of product
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	156	97	446	289
Cost of digital and other
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	217	124	555	338
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	1,986	1,224	5,284	3,490
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	3,853	1,623	8,144	4,175
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	$ 3,677	$ 3,249	$ 10,439	$ 8,031