XML 97 R83.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Fair Value Measurements, Fair Value Hierarchy Table (Details) - USD ($) $ in Millions | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Financial Assets: |  |
Derivative Asset | $ 1.6 | $ 85.7
Deferred compensation plan assets | 7.3 | $ 7.3
Investment Percentage in Industrial Sector |  | 51.00%
Investment Percentage in Financial Sector |  | 37.00%
Investment Percentage in Utilities Sector |  | 12.00%
Financial Liabilities: |  |
Derivative Liabilities | (16.2) | $ (96.8)
Fair Value, Measurements, Recurring |  |
Financial Assets: |  |
Cash and cash equivalents | 72.5 | 177.7
Deferred compensation plan assets | 7.3 | 7.3
Total Assets | 173.2 | 1,171.1
Financial Liabilities: |  |
Convertible Notes, including Bifurcated Conversion Feature |  | (263.3)
Total Liabilities | (223.5) | (604.6)
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Fixed income investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 15.7 | 394.3
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Mortgage backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 30.1
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Corporate debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 75.4
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Equity investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 23.8 | 191.3
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | United States Treasuries |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 39.5
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Municipal debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 1.8
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Cash and money market investments |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1.9 | 19.3
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Asset backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 8.1
Fair Value, Measurements, Recurring | VEBAs and Canadian Pension Plan | Diversified investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 20.4 | 26.6
Fair Value, Measurements, Recurring | Senior Notes |  |
Financial Liabilities: |  |
Senior Notes | (207.3) | (244.5)
Fair Value, Measurements, Recurring | Debt Securities |  |
Financial Assets: |  |
Short-term investments | 30.0 | 114.0
Fair Value, Measurements, Recurring | Aluminum | Option contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.2 |
Fair Value, Measurements, Recurring | Aluminum | Swap contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.3 |
Financial Liabilities: |  |
Derivative Liabilities | (8.9) | (4.2)
Fair Value, Measurements, Recurring | Aluminum | Swap contracts | Sale |  |
Financial Assets: |  |
Derivative Asset | 0.2 |
Financial Liabilities: |  |
Derivative Liabilities | (0.1) |
Fair Value, Measurements, Recurring | Aluminum | Midwest premium swap contracts |  |
Financial Assets: |  |
Derivative Asset | 0.9 | 1.0
Fair Value, Measurements, Recurring | Natural Gas | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | (6.7) | (6.2)
Fair Value, Measurements, Recurring | Electricity | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities |  | (1.7)
Fair Value, Measurements, Recurring | Hedges Relating to the Convertible Notes | Call Options |  |
Financial Assets: |  |
Derivative Asset |  | 84.7
Fair Value, Measurements, Recurring | Hedges Relating to the Convertible Notes | Bifurcated Conversion Feature |  |
Financial Liabilities: |  |
Derivative Liabilities |  | (84.7)
Fair Value, Measurements, Recurring | Level 1 |  |
Financial Assets: |  |
Cash and cash equivalents | 40.3 | 29.5
Deferred compensation plan assets | 0.0 | 0.0
Total Assets | 56.9 | 123.2
Financial Liabilities: |  |
Convertible Notes, including Bifurcated Conversion Feature |  | (263.3)
Total Liabilities | (207.3) | (507.8)
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Fixed income investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 54.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Mortgage backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Corporate debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Equity investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | United States Treasuries |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Municipal debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Cash and money market investments |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1.9 | 19.3
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Asset backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | VEBAs and Canadian Pension Plan | Diversified investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 14.7 | 20.4
Fair Value, Measurements, Recurring | Level 1 | Senior Notes |  |
Financial Liabilities: |  |
Senior Notes | (207.3) | (244.5)
Fair Value, Measurements, Recurring | Level 1 | Debt Securities |  |
Financial Assets: |  |
Short-term investments | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 1 | Aluminum | Option contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Fair Value, Measurements, Recurring | Level 1 | Aluminum | Swap contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 1 | Aluminum | Swap contracts | Sale |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 |
Fair Value, Measurements, Recurring | Level 1 | Aluminum | Midwest premium swap contracts |  |
Financial Assets: |  |
Derivative Asset | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 1 | Natural Gas | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 1 | Electricity | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | Hedges Relating to the Convertible Notes | Call Options |  |
Financial Assets: |  |
Derivative Asset |  | 0.0
Fair Value, Measurements, Recurring | Level 1 | Hedges Relating to the Convertible Notes | Bifurcated Conversion Feature |  |
Financial Liabilities: |  |
Derivative Liabilities |  | 0.0
Fair Value, Measurements, Recurring | Level 2 |  |
Financial Assets: |  |
Cash and cash equivalents | 32.2 | 148.2
Short-term investments | 30.0 |
Deferred compensation plan assets | 7.3 | 7.3
Total Assets | 115.4 | 1,046.9
Financial Liabilities: |  |
Convertible Notes, including Bifurcated Conversion Feature |  | 0.0
Total Liabilities | (15.9) | (96.8)
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Fixed income investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 15.7 | 340.3
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Mortgage backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 30.1
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Corporate debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 75.4
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Equity investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 23.8 | 191.3
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | United States Treasuries |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 39.5
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Municipal debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 1.8
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Cash and money market investments |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Asset backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 8.1
Fair Value, Measurements, Recurring | Level 2 | VEBAs and Canadian Pension Plan | Diversified investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 5.7 | 6.2
Fair Value, Measurements, Recurring | Level 2 | Senior Notes |  |
Financial Liabilities: |  |
Senior Notes | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 2 | Debt Securities |  |
Financial Assets: |  |
Short-term investments |  | 114.0
Fair Value, Measurements, Recurring | Level 2 | Aluminum | Option contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.2 |
Fair Value, Measurements, Recurring | Level 2 | Aluminum | Swap contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.3 |
Financial Liabilities: |  |
Derivative Liabilities | (8.9) | (4.2)
Fair Value, Measurements, Recurring | Level 2 | Aluminum | Swap contracts | Sale |  |
Financial Assets: |  |
Derivative Asset | 0.2 |
Financial Liabilities: |  |
Derivative Liabilities | (0.1) |
Fair Value, Measurements, Recurring | Level 2 | Aluminum | Midwest premium swap contracts |  |
Financial Assets: |  |
Derivative Asset | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 2 | Natural Gas | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | (6.7) | (6.2)
Fair Value, Measurements, Recurring | Level 2 | Electricity | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities |  | (1.7)
Fair Value, Measurements, Recurring | Level 2 | Hedges Relating to the Convertible Notes | Call Options |  |
Financial Assets: |  |
Derivative Asset |  | 84.7
Fair Value, Measurements, Recurring | Level 2 | Hedges Relating to the Convertible Notes | Bifurcated Conversion Feature |  |
Financial Liabilities: |  |
Derivative Liabilities |  | (84.7)
Fair Value, Measurements, Recurring | Level 3 |  |
Financial Assets: |  |
Cash and cash equivalents | 0.0 | 0.0
Deferred compensation plan assets | 0.0 | 0.0
Total Assets | 0.9 | 1.0
Financial Liabilities: |  |
Convertible Notes, including Bifurcated Conversion Feature |  | 0.0
Total Liabilities | (0.3) | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Fixed income investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Mortgage backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Corporate debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Equity investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | United States Treasuries |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Municipal debt securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Cash and money market investments |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Asset backed securities |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | VEBAs and Canadian Pension Plan | Diversified investment funds in registered investment companies |  |
Financial Assets: |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | Senior Notes |  |
Financial Liabilities: |  |
Senior Notes | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | Debt Securities |  |
Financial Assets: |  |
Short-term investments | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | Aluminum | Option contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Fair Value, Measurements, Recurring | Level 3 | Aluminum | Swap contracts | Purchase |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | Aluminum | Swap contracts | Sale |  |
Financial Assets: |  |
Derivative Asset | 0.0 |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 |
Fair Value, Measurements, Recurring | Level 3 | Aluminum | Midwest premium swap contracts |  |
Financial Assets: |  |
Derivative Asset |  | 1.0
Fair Value, Measurements, Recurring | Level 3 | Natural Gas | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 | 0.0
Fair Value, Measurements, Recurring | Level 3 | Electricity | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | Hedges Relating to the Convertible Notes | Call Options |  |
Financial Assets: |  |
Derivative Asset |  | 0.0
Fair Value, Measurements, Recurring | Level 3 | Hedges Relating to the Convertible Notes | Bifurcated Conversion Feature |  |
Financial Liabilities: |  |
Derivative Liabilities |  | $ 0.0
Income Approach Valuation Technique | Fair Value, Measurements, Recurring | Aluminum | Midwest premium swap contracts |  |
Financial Liabilities: |  |
Derivative Liabilities | (0.3) |
Income Approach Valuation Technique | Fair Value, Measurements, Recurring | Level 1 | Aluminum | Midwest premium swap contracts |  |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 |
Income Approach Valuation Technique | Fair Value, Measurements, Recurring | Level 2 | Aluminum | Midwest premium swap contracts |  |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 |
Income Approach Valuation Technique | Fair Value, Measurements, Recurring | Level 3 | Aluminum | Midwest premium swap contracts |  |
Financial Assets: |  |
Derivative Asset | 0.9 |
Financial Liabilities: |  |
Derivative Liabilities | (0.3) |
Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Foreign Currency | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | (0.2) |
Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 1 | Foreign Currency | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | 0.0 |
Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 2 | Foreign Currency | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | (0.2) |
Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 3 | Foreign Currency | Swap contracts | Purchase |  |
Financial Liabilities: |  |
Derivative Liabilities | $ 0.0 |

X
- Definition Investment Percentage in Financial Sector + References No definition available. + Details
Name: | kalu_InvestmentPercentageInFinancialSector
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Investment Percentage in Industrial Sector + References No definition available. + Details
Name: | kalu_InvestmentPercentageInIndustrialSector
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Investment Percentage in Utilities Sector + References No definition available. + Details
Name: | kalu_InvestmentPercentageInUtilitiesSector
Namespace Prefix: | kalu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
Name: | us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Convertible Security -URI http://asc.fasb.org/extlink&oid=6509036 + Details
Name: | us-gaap_ConvertibleDebtFairValueDisclosures
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/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13476-108611 + Details
Name: | us-gaap_DebtInstrumentFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of assets held under deferred compensation agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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_DeferredCompensationPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=49178875&loc=d3e12355-114930 Reference 2: 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=58740216&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13495-108611 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13495-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13433-108611 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_FixedIncomeFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=kalu_DiversifiedInvestmentFundsInRegisteredInvestmentCompaniesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_DebtSecuritiesMember
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: | us-gaap_DerivativeByNatureAxis=us-gaap_OptionOnSecuritiesMember
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_DerivativeByNatureAxis=us-gaap_SwapMember
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_DerivativeByNatureAxis=kalu_MidwestPremiumSwapContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=us-gaap_CallOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=us-gaap_EmbeddedDerivativeFinancialInstrumentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
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=kalu_ForeignCurrencyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |