v3.10.0.1

Restructuring Charges - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018 USD ($) ft²	Mar. 31, 2018 USD ($)	Sep. 29, 2018 USD ($) ft²	Sep. 30, 2017 USD ($)
Capital Leased Assets [Line Items]
Lease obligation				$ 3,100
Deferred rent liability				$ 2,600
Impairment of leasehold	$ 500
Restructuring charges	$ 100	$ 500	$ 187
Massachusetts
Capital Leased Assets [Line Items]
Area of real estate property | ft²	108,743		108,743
Massachusetts | Property Subject to Operating Lease
Capital Leased Assets [Line Items]
Area of real estate property | ft²	25,812		25,812
Restructuring charges	$ 100	$ 500

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