Sales of Assets and Business Units, Business Combinations, and Goodwill (Details) - USD ($)			1 Months Ended		3 Months Ended		12 Months Ended
	Sep. 30, 2017	Mar. 10, 2015	Sep. 30, 2017	Apr. 30, 2016	Jul. 01, 2017	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016	Dec. 04, 2014
Sales of Assets and Business Units
Note receivable resulting from sale of assets and business units							$ 3,050,000	$ 0	$ 0
Gain (loss) on sale of assets and business units							(1,496,000)	2,646,000	0
Proceeds from sale of assets and business units, net of cash sold							967,000	1,972,000	0
Goodwill [Abstract]
Goodwill impairment							0	0	12,700,000
Goodwill [Roll Forward]
Beginning balance						$ 267,549,000	269,758,000	267,549,000
Additions							0	2,209,000
Disposals							(2,244,000)	0
Ending balance							$ 267,514,000	$ 269,758,000	$ 267,549,000
Silicon Image, Inc
Business Combinations [Abstract]
Interests acquired		100.00%								7.00%
Total purchase consideration		$ 588,500,000
Goodwill [Abstract]
Acquisition purchase price consideration adjustment, long-term liabilities related to uncertain tax position						2,100,000
Acquisition purchase price consideration tax-related adjustment						$ 100,000
Hyderabad, India subsidiary and assets related to Simplay Labs testing and certification business | Disposed of by Sale
Sales of Assets and Business Units
Consideration of disposed group	$ 5,300,000		$ 5,300,000
Cash received from sale of business unit	2,300,000
Note receivable resulting from sale of assets and business units	3,000,000		3,000,000
Gain (loss) on sale of assets and business units	$ (1,800,000)
Goodwill [Roll Forward]
Disposals			$ (2,200,000)
Hyderabad | Disposed of by Sale
Sales of Assets and Business Units
Ownership percentage	100.00%		100.00%
Qterics | Disposed of by Sale
Sales of Assets and Business Units
Gain (loss) on sale of assets and business units				$ 2,600,000
Proceeds from sale of assets and business units, net of cash sold				$ 2,000,000	$ 300,000