XML 26 R124.htm IDEA: XBRL DOCUMENT v2.4.1.9
Financial Derivatives and Hedging Activities - Income or Loss from Derivative Instruments Recognized in Results of Operations (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]                  
Derivative instruments, gain (loss) $ (487)us-gaap_DerivativeGainLossOnDerivativeNet $ (115)us-gaap_DerivativeGainLossOnDerivativeNet $ (194)us-gaap_DerivativeGainLossOnDerivativeNet $ (154)us-gaap_DerivativeGainLossOnDerivativeNet $ (3,969)us-gaap_DerivativeGainLossOnDerivativeNet $ (1,761)us-gaap_DerivativeGainLossOnDerivativeNet      
Forward Foreign Currency Exchange Contracts [Member] | Costs of Products Sold [Member] | Designated as Hedging [Member]                  
Derivative Instruments, Gain (Loss) [Line Items]                  
Effective portion of derivative instruments, gain (loss)             (655)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_CostOfSalesMember
(945)us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_CostOfSalesMember
2,183us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_CostOfSalesMember
Forward Foreign Currency Exchange Contracts [Member] | Other - Net [Member] | Designated as Hedging [Member]                  
Derivative Instruments, Gain (Loss) [Line Items]                  
Ineffective portion of derivative instruments, gain (loss)             184us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember
38us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember
311us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeIneffectivePortionAndAmountExcludedFromEffectivenessTestingNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember
Forward Foreign Currency Exchange Contracts [Member] | Other - Net [Member] | Not Designated as Hedging [Member]                  
Derivative Instruments, Gain (Loss) [Line Items]                  
Derivative instruments, gain (loss)             $ 1,599us-gaap_DerivativeGainLossOnDerivativeNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember
$ (455)us-gaap_DerivativeGainLossOnDerivativeNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember
$ (696)us-gaap_DerivativeGainLossOnDerivativeNet
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeForwardMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_IncomeStatementLocationAxis
= glt_OtherNetMember