Significant Components of Deferred Tax Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Vacation, warranty and other accruals	$ 1,269	$ 1,489
Depreciation and amortization	1,554	1,391
Intangible amortization	3,235	4,956
Inventory valuation	1,706	1,547
Deferred income	43	1,132
Equity-based compensation	6,242	7,440
Net operating loss, research and other tax credit carryforwards	43,203	35,693
Other	49	127
Deferred Tax Assets, Gross, Total	57,301	53,775
Valuation allowance for deferred tax assets	(45,859)	(38,998)
Total deferred tax assets	11,442	14,777
Deferred tax liabilities:
Purchased technology	(1,488)	(1,653)
Unbilled revenue	(1,004)	(1,925)
Other	(284)	(304)
Total deferred tax liabilities	(2,776)	(3,882)
Net deferred tax assets	8,666	10,895
As reported on the balance sheet:
Current deferred tax assets	103
Non-current deferred tax assets	9,502	12,176
Current deferred tax liability	(939)	(1,281)
Net deferred tax assets	$ 8,666	$ 10,895