Goodwill and Identified Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	Oct. 02, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
2015 (remaining three months)	$ 1,532
2016	4,096
Total future amortization expense	5,628	$ 10,599
Product cost of revenue [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2015 (remaining three months)	86
2016	0
Total future amortization expense	86
Operating Expenses [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2015 (remaining three months)	1,446
2016	4,096
Total future amortization expense	$ 5,542