Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended
Apr. 01, 2018	Apr. 02, 2017
Segment Reporting Information [Line Items]
Acquisition related expense	$ 800
Restructuring and other-employee severance	(313)	$ 2,511
Contingent consideration adjustment	(4,968)	634
Universal Robots
Segment Reporting Information [Line Items]
Contingent consideration adjustment	(5,000)	600
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	2,166	1,319
Semiconductor Test \| Severance And Benefits
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	3,761	(265)
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	320	885
Industrial Automation
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	200
Restructuring and other-employee severance	120	624
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	836	522
Restructuring and other-employee severance		1,313
Corporate and Other \| Restructuring and other
Segment Reporting Information [Line Items]
Acquisition related expense	774
Restructuring and other-employee severance		205
Corporate and Other \| Universal Robots \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	$ (4,968)	$ 634

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e1043-128460

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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/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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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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