Amortization Expense of Company's Purchased Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Finite Lived Intangible Assets [Line Items]
Cost of goods sold	$ 709	$ 738	$ 2,137	$ 1,937
Amortization of purchased intangible assets	378	381	1,136	1,128
Operating expenses [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	378	381	1,136	1,128
Cost Of Goods Sold And Operating Expense [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 1,087	$ 1,119	$ 3,273	$ 3,065