XML 55 R47.htm IDEA: XBRL DOCUMENT
v3.24.2

Derivatives, Hedging Programs and Other Financial Instruments - Summary of Derivative Positions (Details) - 6 months ended Jun. 30, 2024 Mmlb in Millions | EUR (€) MWh Mmlb MMBTU | GBP (£) MWh Mmlb MMBTU
--- | --- | ---
Purchase | Aluminum |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | 62.4 | 62.4
Purchase | Aluminum | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Purchase | Aluminum | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Dec. 31, 2025 |
Purchase | Fixed Price Purchase Contracts for MWTP |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | 48.9 | 48.9
Purchase | Fixed Price Purchase Contracts for MWTP | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Purchase | Fixed Price Purchase Contracts for MWTP | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Dec. 31, 2025 |
Purchase | Alloying Metals |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | 10.0 | 10.0
Purchase | Alloying Metals | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Purchase | Alloying Metals | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Dec. 31, 2026 |
Purchase | Natural Gas |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | MMBTU | 3,240,000 | 3,240,000
Purchase | Natural Gas | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Purchase | Natural Gas | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Dec. 31, 2026 |
Purchase | Electricity |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | MWh | 110,425 | 110,425
Purchase | Electricity | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Purchase | Electricity | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Dec. 31, 2024 |
Purchase | Euro |  |
Derivative [Line Items] |  |
Derivative notional amount | € | € 10,856,964 |
Purchase | Euro | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Aug. 31, 2024 |
Purchase | Euro | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jan. 31, 2026 |
Purchase | British Pounds |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Derivative notional amount | £ |  | £ 72,266
Sales | Fixed Price Sale Contracts for MWTP |  |
Derivative [Line Items] |  |
Derivative non-monetary notional amount | 15.5 | 15.5
Sales | Fixed Price Sale Contracts for MWTP | Minimum |  |
Derivative [Line Items] |  |
Derivative maturity period | Jul. 31, 2024 |
Sales | Fixed Price Sale Contracts for MWTP | Maximum |  |
Derivative [Line Items] |  |
Derivative maturity period | Sep. 30, 2024 |

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date derivative contract ends, in YYYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480524/946-210-50-6 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 55 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480493/946-210-55-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480524/946-210-50-6 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-5 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5C -Subparagraph (SX 210.12-13C(Column D)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-5C Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column F)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-5 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5A -Subparagraph (SX 210.12-13A(Column C)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-5A Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5B -Subparagraph (SX 210.12-13B(Column D)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-5B + Details
Name: | us-gaap_DerivativeMaturityDates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal number of units used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1I -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 18 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-18 Reference 4: 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 5: 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_DerivativeNonmonetaryNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

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_PositionAxis=us-gaap_LongMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | srt_ReserveQuantitiesByTypeOfReserveAxis=srt_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=us-gaap_ElectricityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_GBP
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=kalu_FixedPriceSaleContractsForMidwestTransactionPriceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |