Segment Information (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) segment product_line	Apr. 01, 2018 USD ($)
Revenue from External Customer [Line Items]
Number of reportable segments \| segment	4
Net sales	$ 745.2	$ 695.6
Aerospace and Defense Electronics
Revenue from External Customer [Line Items]
Net sales	$ 180.4	173.6
Number of Product Lines \| product_line	1
Engineered Systems
Revenue from External Customer [Line Items]
Net sales	$ 73.0	72.0
Instrumentation
Revenue from External Customer [Line Items]
Net sales	$ 256.5	239.0
Number of Product Lines \| product_line	3
Digital Imaging
Revenue from External Customer [Line Items]
Net sales	$ 235.3	$ 211.0

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration