XML 88 R71.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Derivatives and Other Financial Instruments - Schedule of Reconciliation of Activity for Derivative Contracts (Detail) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2016 | Sep. 30, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets, Purchases, sales, issuances, and settlements | $ 0 | $ 0
Embedded Aluminum Derivative [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets, Beginning balance | 745,000,000 | 1,135,000,000
Fair value measurement, Assets, Other comprehensive income | 414,000,000 | (750,000,000)
Fair value measurement, Assets, Transfers into and/or out of Level 3 | 0 | 0
Fair value measurement, Assets, Other | 14,000,000 | 39,000,000
Fair value measurement, Assets, Ending balance | 310,000,000 | 310,000,000
Fair value measurement, Assets, Sales | 0 | 0
Fair value measurement, Assets, Cost of goods sold | 0 | 0
Fair value measurement, Liabilities, Beginning balance | 228,000,000 | 169,000,000
Fair value measurement, Liabilities, Other comprehensive (loss) income | 48,000,000 | 80,000,000
Fair value measurement, Liabilities, Purchases, sales, issuances, and settlements |  | 32,000,000
Fair value measurement, Liabilities, Transfers into and/or out of Level 3 | 0 | 0
Fair value measurement, Liabilities, Other | (3,000,000) | (3,000,000)
Fair value measurement, Liabilities, Ending balance | 272,000,000 | 272,000,000
Fair value measurement, Liabilities, Sales | 0 | 0
Fair value measurement, Liabilities, Cost of goods sold | 0 | 0
Fair value measurement, Liabilities, Other income, net | 2,000,000 | 2,000,000
Embedded Aluminum Derivative [Member] | Sales [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets | 1,000,000 | (9,000,000)
Fair value measurement, Assets | 1,000,000 | (9,000,000)
Fair value measurement, Liabilities | (3,000,000) | (8,000,000)
Embedded Aluminum Derivative [Member] | Other Income [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets | (5,000,000) | (13,000,000)
Fair value measurement, Assets | (5,000,000) | (13,000,000)
Fair value measurement, Liabilities | 2,000,000 | 2,000,000
Embedded Aluminum Derivative [Member] | Cost of Goods Sold [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets | (31,000,000) | (92,000,000)
Fair value measurement, Assets | (31,000,000) | (92,000,000)
Embedded Credit Derivative [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Liabilities, Beginning balance | 33,000,000 | 35,000,000
Fair value measurement, Liabilities, Cost of goods sold | (1,000,000) | (4,000,000)
Fair value measurement, Liabilities, Transfers into and/or out of Level 3 | 0 | 0
Fair value measurement, Liabilities, Ending balance | 24,000,000 | 24,000,000
Fair value measurement, Liabilities, Sales | 0 | 0
Fair value measurement, Liabilities, Cost of goods sold | 0 | 0
Fair value measurement, Liabilities, Other income, net | (8,000,000) | (7,000,000)
Embedded Credit Derivative [Member] | Other Income [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Liabilities | (8,000,000) | (7,000,000)
Energy Contracts [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets, Beginning balance | 49,000,000 | 2,000,000
Fair value measurement, Assets, Other comprehensive income | (48,000,000) | 87,000,000
Fair value measurement, Assets, Transfers into and/or out of Level 3 | 0 | 0
Fair value measurement, Assets, Other | (5,000,000) | 1,000,000
Fair value measurement, Assets, Ending balance | 7,000,000 | 7,000,000
Fair value measurement, Assets, Sales | 0 | 0
Fair value measurement, Assets, Cost of goods sold | 0 | 0
Fair value measurement, Liabilities, Beginning balance | 9,000,000 | 4,000,000
Fair value measurement, Liabilities, Other comprehensive (loss) income | (1,000,000) | (1,000,000)
Fair value measurement, Liabilities, Transfers into and/or out of Level 3 | 0 | 0
Fair value measurement, Liabilities, Other | (7,000,000) | (1,000,000)
Fair value measurement, Liabilities, Sales | 0 | 0
Fair value measurement, Liabilities, Cost of goods sold | 0 | 0
Fair value measurement, Liabilities, Other income, net | (1,000,000) | (2,000,000)
Energy Contracts [Member] | Other Income [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value measurement, Assets | (85,000,000) | (83,000,000)
Fair value measurement, Assets | (85,000,000) | (83,000,000)
Fair value measurement, Liabilities | $ (1,000,000) | $ (2,000,000)

X
- Definition Fair value assets measured on recurring basis gain loss included in cost of goods sold. + References No definition available. + Details
Name: | arnc_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInCostOfGoodsSold
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value assets measured on recurring basis gain loss included in sales. + References No definition available. + Details
Name: | arnc_FairValueAssetsMeasuredOnRecurringBasisGainLossIncludedInSales
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value liabilities measured on recurring basis gain loss included in cost of goods sold. + References No definition available. + Details
Name: | arnc_FairValueLiabilitiesMeasuredOnRecurringBasisGainLossIncludedInCostOfGoodsSold
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value liabilities measured on recurring basis gain loss included in other expenses. + References No definition available. + Details
Name: | arnc_FairValueLiabilitiesMeasuredOnRecurringBasisGainLossIncludedInOtherExpenses
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value liabilities measured on recurring basis gain loss included in sales. + References No definition available. + Details
Name: | arnc_FairValueLiabilitiesMeasuredOnRecurringBasisGainLossIncludedInSales
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value measurement with unobservable inputs reconciliation recurring basis asset increase decrease other. + References No definition available. + Details
Name: | arnc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIncreaseDecreaseOther
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value measurement with unobservable inputs reconciliation recurring basis liabilities gain loss included in cost of goods sold. + References No definition available. + Details
Name: | arnc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitiesGainLossIncludedInCostOfGoodsSold
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value measurement with unobservable inputs reconciliation recurring basis liabilities increase decrease other. + References No definition available. + Details
Name: | arnc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitiesIncreaseDecreaseOther
Namespace Prefix: | arnc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

X
- Definition Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(1) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(1a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(2) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy. + References No definition available. + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(1) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(1a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInOtherComprehensiveIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c)(2) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityPurchasesSalesIssuancesSettlements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of transfers of financial instrument classified as a liability into (out of) level 3 of the fair value hierarchy. + References No definition available. + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + 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 (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
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=arnc_EmbeddedCreditDerivativeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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