Summary of Accrual Activities by Components Related to Company's Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 03, 2015	Mar. 28, 2014
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	$ 231
Restructuring charges	1,753	28
Cash payments	(542)
Non-cash write-offs and other adjustments	(328)
Accrued expense ending balance	1,114
Employee Severance
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	102
Restructuring charges	1,328
Cash payments	(366)
Non-cash write-offs and other adjustments	4
Accrued expense ending balance	1,068
Facility
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	105
Restructuring charges	58
Cash payments	(130)
Accrued expense ending balance	33
Depreciation
Restructuring Cost And Reserve [Line Items]
Restructuring charges	332
Non-cash write-offs and other adjustments	(332)
Other Restructuring Charges
Restructuring Cost And Reserve [Line Items]
Accrued expense beginning balance	24
Restructuring charges	35
Cash payments	(46)
Accrued expense ending balance	$ 13