Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 128
Charged to costs & expenses	38	$ 128
Deductions	128
Balance at end of period	38	128
Inventory Reserve [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	30,009	23,355	$ 25,249
Charged to costs & expenses	5,893	7,006	6,406
Deductions	1,740	352	8,300
Balance at end of period	34,162	30,009	23,355
Warranty Liability [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	8,623	9,724	8,548
Charged to costs & expenses	4,569	7,392	6,951
Deductions	4,798	8,493	5,775
Balance at end of period	8,394	8,623	9,724
Deferred Tax Asset Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	5,816	6,006	6,149
Charged to costs & expenses	43,560		18
Deductions	760	190	161
Balance at end of period	$ 48,616	$ 5,816	$ 6,006