XML 99 R80.htm IDEA: XBRL DOCUMENT
v3.23.3

FINANCIAL DERIVATIVES AND HEDGING ACTIVITIES - Outstanding Derivatives Used to Hedge Foreign Exchange Risks (Details) ₱ in Thousands, € in Thousands, ¥ in Thousands, £ in Thousands, SFr in Thousands, $ in Thousands, $ in Thousands | Sep. 30, 2023 EUR (€) | Sep. 30, 2023 PHP (₱) | Sep. 30, 2023 USD ($) | Sep. 30, 2023 CAD ($) | Sep. 30, 2023 GBP (£) | Sep. 30, 2023 CHF (SFr) | Sep. 30, 2023 CNY (¥) | Dec. 31, 2022 EUR (€) | Dec. 31, 2022 PHP (₱) | Dec. 31, 2022 USD ($) | Dec. 31, 2022 CAD ($) | Dec. 31, 2022 GBP (£) | Dec. 31, 2022 CHF (SFr) | Dec. 31, 2022 CNY (¥)
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Euro / British Pound | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | € 0 |  |  |  |  |  |  | € 0 |  |  |  |  |  |
U.S. Dollar / British Pound | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | $ 14,100 |  |  |  |  |  |  | $ 28,600 |  |  |  |
Euro / U.S. Dollar | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | 9,740 |  |  |  |  |  |  | 9,630 |  |  |  |  |  |
Euro / U.S. Dollar | Not Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | 4,500 |  |  |  |  |  |  | 2,900 |  |  |  |  |  |
British Pound / Euro | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | £ 3,100 |  |  |  |  |  |  | £ 2,800 |  |
British Pound / Euro | Not Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | 2,700 |  |  |  |  |  |  | 15,950 |  |
U.S. Dollar / Swiss Franc | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | 6,970 |  |  |  |  |  |  | 0 |  |  |  |
British Pound / Swiss Franc | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | 1,930 |  |  |  |  |  |  | 2,535 |  |
Euro / Swiss Franc | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | 1,270 |  |  |  |  |  |  | 0 |  |  |  |  |  |
U.S Dollar / Philippine Peso | Not Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | 7,200 |  |  |  |  |  |  | 0 |  |  |  |
Swiss Franc / Euro | Not Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | SFr |  |  |  |  |  | SFr 0 |  |  |  |  |  |  | SFr 2,250 |
Swiss Franc / U.S. Dollar | Not Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | SFr |  |  |  |  |  | SFr 0 |  |  |  |  |  |  | SFr 930 |
Chinese Yuan / U.S. Dollar | Not Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | ¥ |  |  |  |  |  |  | ¥ 0 |  |  |  |  |  |  | ¥ 4,400
Cash Flow Hedges | Euro / British Pound | Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | 12,679 |  |  |  |  |  |  | 18,961 |  |  |  |  |  |
Cash Flow Hedges | Philippine Peso / Euro | Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | ₱ |  | ₱ 183,120 |  |  |  |  |  |  | ₱ 0 |  |  |  |  |
Cash Flow Hedges | U.S. Dollar / British Pound | Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | 26,817 |  |  |  |  |  |  | 34,501 |  |  |  |
Cash Flow Hedges | U.S. Dollar / Euro | Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | 0 |  |  |  |  |  |  | 824 |  |  |  |
Cash Flow Hedges | Canadian Dollar / U.S. Dollar | Designated as Hedging | Sell/Buy - sell notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  |  | $ 0 |  |  |  |  |  |  | $ 0 |  |  |
Cash Flow Hedges | Euro / Philippine Peso | Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | 1,044,331 |  |  |  |  |  |  | 1,030,114 |  |  |  |  |  |
Cash Flow Hedges | British Pound / Philippine Peso | Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | 765,097 |  |  |  |  |  |  | 1,144,839 |  |
Cash Flow Hedges | Euro / U.S. Dollar | Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € | € 93,831 |  |  |  |  |  |  | € 78,435 |  |  |  |  |  |
Cash Flow Hedges | U.S. Dollar / Canadian Dollar | Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ |  |  | $ 31,158 |  |  |  |  |  |  | $ 36,423 |  |  |  |
Cash Flow Hedges | British Pound / U.S. Dollar | Designated as Hedging | Sell/Buy - buy notional |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | £ 8,335 |  |  |  |  |  |  | £ 0 |  |

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_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_EuroToBritishPoundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_USDollarToBritishPoundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_EuroToUSDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_BritishPoundToEuroMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_USDollarToSwissFrancMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_BritishPoundToSwissFrancMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_EuroToSwissFrancMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_USDollarToPhilippinePesoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_SwissFrancToEuroMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_SwissFrancToUSDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_ChineseYuanToUSDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_PhilippinePesoToEuroMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_USDollarToEuroMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_CanadianDollarToUSDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_EuroToPhilippinePesoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_BritishPoundToPhilippinePesoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_UsDollarToCanadianDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=glt_BritishPoundToUSDollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |