Goodwill and Identified Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 29, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	$ 4,174
2019	8,347
2020	3,987
2021	502
Total future amortization expense	17,010	$ 21,279
Cost of Sales [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	2,590
2019	5,180
2020	951
2021	0
Total future amortization expense	8,721
Operating Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2018 (remaining six months)	1,584
2019	3,167
2020	3,036
2021	502
Total future amortization expense	$ 8,289