Revenue Recognition - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue Recognition [Abstract]
Revenue recognized from contract liability			$ 200	$ 300
Contract With Customer Liability Revenue Recognized Extended Warranty			1,100	$ 2,000
Undelivered elements (product training, installation, product and support services)	$ 1,015		$ 1,015		$ 670
Revenue from services transferred to customers over time, percentage	12.00%	14.00%	12.00%	22.00%
Revenue from products and services transferred to customers, percentage	88.00%	86.00%	88.00%	78.00%