Goodwill and Identified Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 26, 2020	Dec. 31, 2019
Acquired Finite-Lived Intangible Assets [Line Items]
2020 (remaining six months)	$ 1,495
2021	498
Total future amortization expense	1,993	$ 4,461
Cost of Revenue [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2020 (remaining six months)	0
2021	0
Total future amortization expense	0
Operating Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
2020 (remaining six months)	1,495
2021	498
Total future amortization expense	$ 1,993