Summary of Accrual Activities by Components Related to Company's Restructuring Charges (Details) $ in Thousands	6 Months Ended
	Jun. 29, 2018 USD ($)
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	$ 806
Restructuring charges	988
Cash payments	(269)
Non-cash write-offs and other adjustments	(7)
Accrued expense ending balance	1,518
Severance
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	39
Restructuring charges	945
Cash payments	(38)
Non-cash write-offs and other adjustments	(7)
Accrued expense ending balance	939
Facility
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	763
Cash payments	(188)
Accrued expense ending balance	575
Other Restructuring Charges
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	4
Restructuring charges	43
Cash payments	(43)
Accrued expense ending balance	$ 4