Intangible Assets (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2018 USD ($)	Jul. 01, 2017 USD ($)	Apr. 01, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jul. 01, 2017 USD ($) Installment	Dec. 30, 2017 USD ($)
Finite-Lived Intangible Assets [Line Items]
Impairment of acquired intangible assets	$ 11,900,000	$ 0		$ 11,900,000	$ 0
Proceeds from sale of intangible assets, number of installments | Installment					2
Accumulated amortization, intangible assets	110,700,000			110,700,000		$ 100,300,000
Amortization of acquired intangible assets	4,646,000	8,878,000		10,409,000	$ 17,565,000
Research and development
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	123,000	141,000		250,000	314,000
Amortization of acquired intangible assets
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangible assets	$ 4,523,000	$ 8,737,000		$ 10,159,000	17,251,000
Patents
Finite-Lived Intangible Assets [Line Items]
Proceeds from sale of intangible assets			$ 18,000,000
Decrease of intangible assets, net of amortization					$ 3,500,000