XML 91 R78.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Debt and Credit Facility, Narrative (Details) | 6 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Jun. 30, 2016 | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Jun. 01, 2016 USD ($) | May 15, 2016 USD ($) | May 23, 2012 USD ($)
Debt Instrument |  |  |  |  |  |  |
Loss on Repurchase of Debt Instrument |  | $ 0 | $ 0 | $ (11,100,000) |  |  |
Long-term debt |  | 370,400,000 | 369,600,000 |  |  |  |
Repayments of Unsecured Debt |  | 0 | 0 | 206,000,000.0 |  |  |
Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Principal amount of notes |  |  |  |  |  | $ 375,000,000.0 |
Interest rate |  |  |  |  |  | 5.875% |
Percentage of principal amount issued |  |  |  |  |  | 100.00% |
Unamortized Debt Issuance Expense |  | 4,600,000 | 5,400,000 |  |  |  |
Interest Expense including amortization of deferred financing cost |  | $ 22,900,000 |  | 14,500,000 |  |  |
Effective interest rate |  | 6.10% |  |  |  |  |
Debt Instrument, Fair Value Disclosure |  | $ 369,900,000 | $ 399,900,000 |  |  |  |
Senior Notes Due 2024 | Senior Notes | Change in control |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 101.00% |  |  |  |  |
Senior Notes Due 2020 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Principal amount of notes |  |  |  |  |  |  | $ 225,000,000.0
Interest rate |  |  |  |  |  |  | 8.25%
Interest Expense including amortization of deferred financing cost |  |  |  | $ 7,100,000 |  |  |
Long-term debt |  |  |  |  | $ 197,800,000 |  |
Revolving Credit Facility | Line of Credit |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Maximum borrowing capacity |  | $ 300,000,000.0 |  |  |  |  |
Percentage of eligible accounts receivable for borrowing base |  | 85.00% |  |  |  |  |
Percentage of eligible inventory for borrowing base |  | 75.00% |  |  |  |  |
Percentage of net orderly liquidation value of eligible inventory |  | 85.00% |  |  |  |  |
Maximum amount of eligible machinery and equipment for borrowing base |  | $ 60,000,000.0 |  |  |  |  |
Line of Credit Facility, Possible Future Maximum Borrowing Capacity |  | 400,000,000.0 |  |  |  |  |
Available borrowing capacity |  | 300,000,000.0 |  |  |  |  |
Outstanding line of credit |  | 0 |  |  |  |  |
Remaining available borrowing capacity |  | $ 292,000,000.0 |  |  |  |  |
Interest on Revolving Credit Facility |  | 5.75% |  |  |  |  |
Minimum Amount of Available Borrowing to Maintain |  | $ 52,500,000 |  |  |  |  |
Revolving Credit Facility | Line of Credit | Borrowing Availability Under $45.0 Million |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Line of Credit, Ability to Make Restricted Actions, Available Borrowing Necessary After Action with Fixed Charge Coverage Ratio |  | $ 45,000,000.0 |  |  |  |  |
Fixed Charge Coverage Ratio |  | 1.15 |  |  |  |  |
Revolving Credit Facility | Line of Credit | Borrowing Availability Under $30.0 Million |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Fixed Charge Coverage Ratio |  | 1.0 |  |  |  |  |
Line of Credit, Minimum Borrowing Availability Threshold to Maintain Fixed Charge Coverage Ratio |  | $ 30,000,000.0 |  |  |  |  |
Revolving Credit Facility | Letter of Credit |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Maximum borrowing capacity |  | 20,000,000.0 |  |  |  |  |
Outstanding line of credit |  | $ (8,000,000.0) |  |  |  |  |
On or after June 1, 2016 | Senior Notes Due 2020 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage | 104.125% |  |  |  |  |  |
On or after May 15, 2019 | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 104.406% |  |  |  |  |
On or after May 15, 2020 | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 102.938% |  |  |  |  |
On or after May 15, 2021 | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 101.469% |  |  |  |  |
On or after May 15, 2022 | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 100.00% |  |  |  |  |
Any time prior to May 15, 2019 | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 100.00% |  |  |  |  |
Upon receipt of the proceeds of certain asset sales | Senior Notes Due 2024 | Senior Notes |  |  |  |  |  |  |
Debt Instrument |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage |  | 100.00% |  |  |  |  |

X
- Definition Debt issuance, percentage of principal amount + References No definition available. + Details
Name: | kalu_Debtissuancepercentageofprincipalamount
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line of Credit, Ability to Make Restricted Actions, Available Borrowing Necessary After Action + References No definition available. + Details
Name: | kalu_LineofCreditAbilitytoMakeRestrictedActionsAvailableBorrowingNecessaryAfterAction
Namespace Prefix: | kalu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line of Credit, Ability to Make Restricted Actions, Available Borrowing Necessary After Action with Fixed Charge Coverage Ratio + References No definition available. + Details
Name: | kalu_LineofCreditAbilitytoMakeRestrictedActionsAvailableBorrowingNecessaryAfterActionwithFixedChargeCoverageRatio
Namespace Prefix: | kalu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line of Credit Facility, Possible Future Maximum Borrowing Capacity + References No definition available. + Details
Name: | kalu_LineofCreditFacilityPossibleFutureMaximumBorrowingCapacity
Namespace Prefix: | kalu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line of Credit, Fixed Charge Coverage Ratio + References No definition available. + Details
Name: | kalu_LineofCreditFixedChargeCoverageRatio
Namespace Prefix: | kalu_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line of Credit, Minimum Borrowing Availability Threshold to Maintain Fixed Charge Coverage Ratio + References No definition available. + Details
Name: | kalu_LineofCreditMinimumBorrowingAvailabilityThresholdtoMaintainFixedChargeCoverageRatio
Namespace Prefix: | kalu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum amount of eligible machinery and equipment for borrowing base + References No definition available. + Details
Name: | kalu_Maximumamountofeligiblemachineryandequipmentforborrowingbase
Namespace Prefix: | kalu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of eligible accounts receivable for borrowing base + References No definition available. + Details
Name: | kalu_Percentageofeligibleaccountsreceivableforborrowingbase
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of eligible inventory for borrowing base + References No definition available. + Details
Name: | kalu_Percentageofeligibleinventoryforborrowingbase
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of net orderly liquidation value of eligible inventory + References No definition available. + Details
Name: | kalu_Percentageofnetorderlyliquidationvalueofeligibleinventory
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611 + Details
Name: | us-gaap_DebtInstrumentFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage price of original principal amount of debt at which debt can be redeemed by the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph e -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase. + References No definition available. + Details
Name: | us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate amount of interest paid or due on all long-term debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.8) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 + Details
Name: | us-gaap_InterestExpenseLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The effective interest rate at the end of the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585 + Details
Name: | us-gaap_RepaymentsOfUnsecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_UnamortizedDebtIssuanceExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=kalu_SeniorNotesDue2024Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | kalu_AccountingChangesAxis=kalu_ChangeInControlMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=kalu_SeniorNotesDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | kalu_DebtCovenantTriggerAxis=kalu_BorrowingAvailabilityUnderFortyFiveMillionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | kalu_DebtCovenantTriggerAxis=kalu_BorrowingAvailabilityUnderThirtyMillionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_OnOrAfterJune12016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_OnorafterMay152019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_OnorafterMay152020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_OnorafterMay152021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_OnorafterMay152022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_AnytimepriortoMay152019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=kalu_UponreceiptoftheproceedsofcertainassetsalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |