Discontinued Operations Narrative (Details) (USD $)	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	$ (260,000)	$ (1,810,000)	$ 2,405,000
(Benefit from) provision for income taxes on discontinued operations and dispositions	(1,831,000)	(5,107,000)	(823,000)
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]
Disposal Group, Including Discontinued Operations, Severance Costs	1,000,000
(Loss) gain on disposition of discontinued operations before income taxes	(90,000)	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	(14,000)	493,000	2,459,000
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	(156,000)	(2,100,000)	0
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	$ (203,000)	$ (54,000)