Segment Information (Sales) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Apr. 01, 2018
Revenue from External Customer [Line Items]
Net sales	$ 745.2	$ 695.6
Instrumentation
Revenue from External Customer [Line Items]
Net sales	256.5	239.0
Operating Segments \| Instrumentation
Revenue from External Customer [Line Items]
Net sales	256.5	239.0
Operating Segments \| Instrumentation \| Marine Instrumentation
Revenue from External Customer [Line Items]
Net sales	105.2	104.2
Operating Segments \| Instrumentation \| Environmental Instrumentation
Revenue from External Customer [Line Items]
Net sales	86.4	81.2
Operating Segments \| Instrumentation \| Test and Measurement Instrumentation
Revenue from External Customer [Line Items]
Net sales	$ 64.9	$ 53.6

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