Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Revenue Arrangement
Maintenance, service and training	$ 81,826	$ 77,654
Customer advances, undelivered elements and other	55,112	63,438
Extended warranty	64,168	51,929	$ 30,677	$ 27,422
Total deferred revenue and customer advances	$ 201,106	$ 193,021