Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Deferred tax assets:
Inventory, receivable and warranty reserves	$ 9,585	$ 13,290
Net operating loss carryforwards	8,266	9,070
Tax credit carryforwards	11,905	11,258
Accrued employee benefits	5,232	3,709
Deferred profit	1,091us-gaap_DeferredTaxAssetsDeferredIncome	839us-gaap_DeferredTaxAssetsDeferredIncome
Stock-based compensation	4,352	3,972
Acquisition basis differences	2,133	2,105
Depreciation and fixed asset related	1,001	831
Other	608us-gaap_DeferredTaxAssetsOther	121us-gaap_DeferredTaxAssetsOther
Gross deferred tax assets	44,173us-gaap_DeferredTaxAssetsGross	45,195us-gaap_DeferredTaxAssetsGross
Less valuation allowance	(37,023)	(36,064)
Total deferred tax assets	7,150us-gaap_DeferredTaxAssetsNet	9,131us-gaap_DeferredTaxAssetsNet
Deferred tax liabilities:
Depreciation and fixed asset related	2,823	2,909
Acquisition basis differences	10,600	13,193
Other	643	461
Total deferred tax liabilities	14,066us-gaap_DeferredTaxLiabilities	16,563us-gaap_DeferredTaxLiabilities
Net deferred tax liabilities	$ (6,916)us-gaap_DeferredTaxAssetsLiabilitiesNet	$ (7,432)us-gaap_DeferredTaxAssetsLiabilitiesNet

Deferred Tax Asset Acquisition Basis Differences

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Deferred Tax Assets Inventory And Warranty Reserves

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Deferred Tax Liabilities Asset Basis Differences

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences not separately disclosed.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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The tax effect as of the balance sheet date of the amount of future tax deductions arising from all unused tax credit carryforwards which have been reduced by a valuation allowance.

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The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from employee benefit costs not otherwise specified in the taxonomy, which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances.

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Amount of deferred tax consequences attributable to taxable temporary differences derived from prepaid expenses.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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