XML 131 R82.htm IDEA: XBRL DOCUMENT v2.4.1.9

Retirement Plans And Postretirement Benefits (Fair Asset Values Of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 77,728us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
U.S. [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	99,454us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember	90,875us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember	91,319us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember
U.S. [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	906us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember	2,597us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember
U.S. [Member] | Collective Trusts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98,548us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember	88,278us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember
U.S. [Member] | Level 1 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	906us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	2,597us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
U.S. [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	906us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	2,597us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
U.S. [Member] | Level 1 [Member] | Collective Trusts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
U.S. [Member] | Level 2 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98,548us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	88,278us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
U.S. [Member] | Level 2 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
U.S. [Member] | Level 2 [Member] | Collective Trusts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98,548us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	88,278us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
U.S. [Member] | Level 3 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
U.S. [Member] | Level 3 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
U.S. [Member] | Level 3 [Member] | Collective Trusts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_CollectiveTrustsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Foreign [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77,728us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember	72,685us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember	71,750us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember
Foreign [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,364us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember	2,549us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember
Foreign [Member] | Foreign Government Bonds [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,038us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember	1,142us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember
Foreign [Member] | Investment Contracts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	61,990us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_InvestmentContractsMember	58,129us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_InvestmentContractsMember
Foreign [Member] | Fixed Insurance Contracts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	13,336us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_FixedInsuranceContractsMember	10,865us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_FixedInsuranceContractsMember
Foreign [Member] | Level 1 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,364us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	2,549us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Foreign [Member] | Level 1 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,364us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	2,549us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Foreign [Member] | Level 1 [Member] | Foreign Government Bonds [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member
Foreign [Member] | Level 2 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,038us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	1,142us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Foreign [Member] | Level 2 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Foreign [Member] | Level 2 [Member] | Foreign Government Bonds [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,038us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	1,142us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Foreign [Member] | Level 3 [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75,326us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	68,994us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Foreign [Member] | Level 3 [Member] | Cash And Cash Equivalents [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
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Foreign [Member] | Level 3 [Member] | Foreign Government Bonds [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_ForeignGovernmentDebtMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Foreign [Member] | Level 3 [Member] | Investment Contracts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	61,990us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_InvestmentContractsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	58,129us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = us-gaap_InvestmentContractsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member
Foreign [Member] | Level 3 [Member] | Fixed Insurance Contracts [Member] | Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 13,336us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_FixedInsuranceContractsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member	$ 10,865us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis = us-gaap_PensionPlansDefinedBenefitMember / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_EligibleItemOrGroupForFairValueOptionAxis = gti_FixedInsuranceContractsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member

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- Definition

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Section 35

-Paragraph 50

-URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930

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