Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred tax assets:
Reserves and accruals	$ 29,235	$ 31,999
Net operating loss carryovers	27,253	27,522
Research and development credit carryovers	18,391	13,704
Deferred stock-based compensation	7,554	7,684
Other tax credits	2,738	2,207
Gross deferred tax assets	85,171	83,116
Valuation allowance	(38,644)	(34,347)	(28,354)	(26,557)
Gross deferred tax assets after valuation allowance	46,527	48,769
Deferred tax liabilities:
Depreciation and amortization	(3,590)	(5,485)
Intangibles	(6,227)	(11,656)
Other	(738)	(483)
Gross deferred tax liabilities	(10,555)	(17,624)
Net deferred tax assets	$ 35,972	$ 31,145