XML 129 R110.htm IDEA: XBRL DOCUMENT
v3.20.4

Schedule of Weighted Average Assumptions to Determine Pension Obligations (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Postretirement Benefit Plans |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 2.20% | 3.00% | 4.00%
Initial medical trend | 7.30% | 7.10% | 7.50%
Ultimate health care trend | 4.50% | 4.50% | 4.50%
Medical cost trend rate decrease to ultimate rate in year | 2029 | 2026 | 2026
UNITED STATES |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 2.20% | 3.00% |
Salary progression rate | 2.40% | 2.60% |
Foreign Pension Plans, Defined Benefit |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 0.70% | 1.10% |
Salary progression rate | 2.30% | 2.50% |

X
- Definition Defined benefit plan assumptions used calculating benefit obligation initial medical trend. + References No definition available. + Details
Name: | ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationInitialMedicalTrend
Namespace Prefix: | ter_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined benefit plan assumptions used calculating benefit obligation medical cost trend rate decrease to ultimate rate in year. + References No definition available. + Details
Name: | ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationMedicalCostTrendRateDecreaseToUltimateRateInYear
Namespace Prefix: | ter_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined benefit plan assumptions used calculating benefit obligation salary progression rate. + References No definition available. + Details
Name: | ter_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationSalaryProgressionRate
Namespace Prefix: | ter_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ultimate trend rate for health care cost for defined benefit postretirement plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanSponsorLocationAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |