XML 63 R50.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Derivatives, Hedging Programs and Other Financial Instruments, Realized and Unrealized Gains (Losses) Table (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2017 | Mar. 31, 2016
Summary Of Realized And Unrealized Gains (Losses) |  |
Unrealized gains (losses) | $ 15.1 | $ 4.0
Operational Risk Hedges | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Unrealized gains (losses) | 15.1 | 4.0
Cost of Sales [Member] | Alloy Metal Hedge [Member] | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Realized (losses) gains | 0.1 | 0.0
Cost of Sales [Member] | Aluminum | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Realized (losses) gains | 4.6 | (2.7)
Cost of Sales [Member] | Operational Risk Hedges | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Realized (losses) gains | 4.7 | (4.4)
Cost of Sales [Member] | Natural Gas | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Realized (losses) gains | 0.0 | (1.7)
Gain (Loss) on Derivative Instruments | Aluminum | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Unrealized gains (losses) | 16.3 | 3.2
Gain (Loss) on Derivative Instruments | Natural Gas | Not Designated as Hedging Instrument |  |
Summary Of Realized And Unrealized Gains (Losses) |  |
Unrealized gains (losses) | $ (1.2) | $ 0.8

X
- Definition Summary Of Realized And Unrealized Gains Losses Abstract. + References No definition available. + Details
Name: | kalu_SummaryOfRealizedAndUnrealizedGainsLossesAbstract
Namespace Prefix: | kalu_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
Name: | us-gaap_UnrealizedGainLossOnDerivatives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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