Segment Information (Reconciliation) (Details) - USD ($) $ in Millions		3 Months Ended
		Apr. 03, 2016	Mar. 29, 2015
Net sales:
Net sales	[1]	$ 530.5	$ 565.0
Net sales, percentage change	[1]	(6.10%)
Operating income:
Total segment operating profit		$ 61.0	67.3
Total segment operating profit, percentage change		(9.40%)
Corporate, Non-Segment
Operating income:
Total segment operating profit		$ (10.7)	(10.2)
Total segment operating profit, percentage change		4.90%
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues		$ 5.1	4.9
Instrumentation | Operating Segments
Net sales:
Net sales	[1]	$ 223.7	270.3
Net sales, percentage change	[1]	(17.20%)
Operating income:
Total segment operating profit		$ 31.4	42.1
Total segment operating profit, percentage change		(25.40%)
Digital Imaging | Operating Segments
Net sales:
Net sales	[1]	$ 89.9	90.4
Net sales, percentage change	[1]	(0.60%)
Operating income:
Total segment operating profit		$ 8.2	9.3
Total segment operating profit, percentage change		(11.80%)
Aerospace and Defense Electronics | Operating Segments
Net sales:
Net sales	[1]	$ 152.6	141.2
Net sales, percentage change	[1]	8.10%
Operating income:
Total segment operating profit		$ 24.1	19.4
Total segment operating profit, percentage change		24.20%
Engineered Systems | Operating Segments
Net sales:
Net sales	[1]	$ 64.3	63.1
Net sales, percentage change	[1]	1.90%
Operating income:
Total segment operating profit		$ 8.0	$ 6.7
Total segment operating profit, percentage change		19.40%

[1] (a)Net sales excludes inter-segment sales of $5.1 million and $4.9 million for the first quarter of 2016 and 2015, respectively.