Extended Product Warranty of Short and Long-Term Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 27,422	$ 24,438	$ 28,200
Deferral of new extended warranty revenue	23,271	23,753	20,513
Recognition of extended warranty deferred revenue	(20,016)	(20,769)	(24,275)
Balance at end of period	$ 30,677	$ 27,422	$ 24,438