Industry Segment Information (Schedule of Sales and Operating Income by Operating Segment, Excluding Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Segment Reporting Information [Line Items]
Product revenue	$ 333,714	$ 324,353
Service revenue	180,401	173,663
Total revenue	514,115	498,016
Operating income (loss) from continuing operations	51,579	60,577
Interest and other expense, net	11,596	11,086
Income from continuing operations before income taxes	39,983	49,491
Change in allocation of functional Costs, Effect on operating income (loss)		3,700
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income (loss) from continuing operations	(12,410)	(12,666)
Diagnostics [Member]
Segment Reporting Information [Line Items]
Product revenue	118,554	104,947
Service revenue	33,801	36,622
Total revenue	152,355	141,569
Operating income (loss) from continuing operations	33,410	33,774
Discovery & Analytical Solutions [Member]
Segment Reporting Information [Line Items]
Product revenue	215,160	219,406
Service revenue	146,600	137,041
Total revenue	361,760	356,447
Operating income (loss) from continuing operations	$ 30,579	$ 39,469