Cost of revenues-provision for excess and obsolete inventory.

No definition available.

Name:	ter_CostOfRevenuesProvisionForExcessAndObsoleteInventory
Namespace Prefix:	ter_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e1043-128460

+ Details

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Balance Type:	debit
Period Type:	duration

- 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)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-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

+ Details

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

- Definition

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

+ References

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=116634182&loc=SL114868664-224227

+ Details

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

- 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.

+ Details

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- Details

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- Details

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Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Segment Reporting Information [Line Items]
Acquisition related costs	$ 500	$ 2,500	$ 1,800	$ 3,300
Restructuring and other-employee severance	(10,404)	2,389	(5,292)	2,076
Contingent consideration adjustment	11,700	3,500	(8,701)	(8,468)
Universal Robots (UR)
Segment Reporting Information [Line Items]
Contingent consideration adjustment		24,600
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	2,278	1,613	3,452	3,779
Semiconductor Test \| Severance And Benefits
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	357	2,179	924	5,940
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	295	256	763	576
Industrial Automation
Segment Reporting Information [Line Items]
Acquisition related costs	434		1,695
Cost of revenues-inventory charge			416
Restructuring and other-employee severance		218		338
Industrial Automation \| Severance And Benefits
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	202		297
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	829	627	1,168	1,463
Corporate And Eliminations \| Restructuring and other
Segment Reporting Information [Line Items]
Acquisition related costs		2,544		3,318
Corporate And Eliminations \| Universal Robots (UR) \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment		$ (3,500)		$ (8,468)
Corporate And Eliminations \| Mobile Industrial Robots (MiR) \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	$ (11,671)		$ (8,668)