XML 129 R108.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Schedule of Weighted Average Assumptions to Determine Pension Obligations (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Postretirement Benefit Plans |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 4.00% | 3.40% | 3.90%
Initial medical trend | 7.50% | 7.90% | 7.30%
Ultimate health care trend | 4.50% | 4.50% | 5.00%
Medical cost trend rate decrease to ultimate rate in year | 2026 | 2026 | 2023
UNITED STATES |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 4.10% | 3.40% |
Salary progression rate | 2.30% | 2.30% |
Foreign Pension Plans, Defined Benefit |  |  |
Defined Benefit Plan Disclosure |  |  |
Discount rate | 1.80% | 1.80% |
Salary progression rate | 2.60% | 2.70% |

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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=108410482&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: |