Discontinued Operations (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016	Jan. 01, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue	$ 36,094	$ 40,766
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	23,794		$ 28,400
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	2,541	5,722
Income from discontinued operations before income taxes	3,759	8,190
Pre-tax gain (loss) on disposal of business unit	0	(3)
Discontinued Operation, Tax Effect of Discontinued Operation	1,218	2,465
Disposal Group, Including Discontinued Operation, Inventory, Current	28,764		26,977
Disposal Group, Including Discontinued Operation, Prepaid income taxes, Current	0		425
Disposal Group, Including Discontinued Operation, Other Assets, Current	3,179		3,183
Disposal Group, Including Discontinued Operation, Assets, Current	55,737		58,985
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent	24,310		25,219
Disposal Group, Including Discontinued Operation, Intangible Assets, Noncurrent	3,012		3,292
Disposal Group, Including Discontinued Operation, Goodwill, Noncurrent	38,974		38,794
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	32		1,084
Long-term assets of discontinued operations	66,328		68,389
Disposal Group, Including Discontinued Operation, Assets	122,065		127,374
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	19,906		16,770
Disposal Group, Including Discontinued Operation, Accrued restructuring and contract termination charges, Current	0		209
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current	11,053		9,992
Current liabilities of discontinued operations	30,959		26,971
Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities, Noncurrent	8,429		7,851
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent	6,835		7,109
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	15,264		14,960
Disposal Group, Including Discontinued Operation, Liabilities	46,223		$ 41,931
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	24,795	25,755
Disposal Group, Including Discontinued Operation, General and Administrative Expense	3,943	3,007
Disposal Group, Including Discontinued Operations, Research and development expenses	3,597	3,814
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	$ 3,759	$ 8,190