Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Apr. 01, 2018
Segment Reporting Information [Line Items]
Acquisition related costs	$ 1,300	$ 800
Restructuring and other-employee severance	5,112	(313)
Contingent consideration adjustment	2,970	(4,968)
Universal Robots (UR)
Segment Reporting Information [Line Items]
Contingent consideration adjustment	3,000	5,000
Mobile Industrial Robots (MiR)
Segment Reporting Information [Line Items]
Contingent consideration adjustment	800
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	1,174	2,166
Semiconductor Test \| Severance And Benefits
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	567	3,761
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	468	320
Industrial Automation
Segment Reporting Information [Line Items]
Acquisition related costs	1,261
Cost of revenues-inventory charge	416	200
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	339	836
Corporate And Eliminations \| Restructuring and other
Segment Reporting Information [Line Items]
Acquisition related costs		774
Corporate And Eliminations \| Universal Robots (UR) \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment		$ (4,968)
Corporate And Eliminations \| Mobile Industrial Robots (MiR) \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	$ 3,003

Cost of revenues-provision for excess and obsolete inventory.

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- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
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- Definition

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
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-Publisher FASB
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-SubTopic 30
-Section 50
-Paragraph 4
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- Definition

Amount of restructuring charges, remediation cost, and asset impairment loss.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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