Discontinued Operations Schedule Of Gains And Losses On Disposition Of Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposition of discontinued operations before income taxes	$ (260)	$ (1,810)	$ 2,405
Other Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposition of discontinued operations before income taxes	0	(203)	(54)
Technical Services Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposition of discontinued operations before income taxes	(156)	(2,100)	0
Microarray-based diagnostic testing laboratory in the United States [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposition of discontinued operations before income taxes	(90)	0	0
Photoflash Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on disposition of discontinued operations before income taxes	$ (14)	$ 493	$ 2,459