Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Net operating losses	$ 347	$ 483
Warranty reserve	13,032	16,085
Stock-based compensation	2,931	2,383
Accruals not currently deductible and other	5,221	6,210
Inventories	4,437	3,843
State tax credit carryforwards	4,050	3,714
Gross deferred tax assets, before valuation allowance	30,018	32,718
Valuation allowance	(4,465)	(4,201)
Gross deferred tax assets, after valuation allowance	25,553	28,517
Deferred tax liabilities:
Depreciation and other	(19,990)	(19,380)
Gross deferred tax liabilities	(19,990)	(19,380)
Net deferred tax asset	$ 5,563	$ 9,137