XML 75 R62.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Debt - Schedule of Long-Term Debt (Detail) - USD ($) $ in Millions | Mar. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Debt Instrument [Line Items] |  |
Long-term debt | $ (6,312) | $ (6,807)
Less: amount due within one year | 3 | 1
Long-term debt, excluding amount due within one year | 6,309 | 6,806
5.72% Notes, due 2019 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ 0 | (500)
Long-term debt, interest rate | 5.72% |
1.63% Convertible Notes, due 2019 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (403) | (403)
Long-term debt, interest rate | 1.63% |
6.150% Notes, due 2020 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (1,000) | (1,000)
Long-term debt, interest rate | 6.15% |
5.40% Notes due 2021 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (1,250) | (1,250)
Long-term debt, interest rate | 5.40% |
5.87% Notes, due 2022 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (627) | (627)
Long-term debt, interest rate | 5.87% |
5.125% Notes, due 2024 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (1,250) | (1,250)
Long-term debt, interest rate | 5.125% |
5.90% Notes, due 2027 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (625) | (625)
Long-term debt, interest rate | 5.90% |
6.75% Bonds, due 2028 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (300) | (300)
Long-term debt, interest rate | 6.75% |
5.95% Notes, due 2037 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (625) | (625)
Long-term debt, interest rate | 5.95% |
Iowa Finance Authority Loan, due 2042 |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (250) | (250)
Other |  |
Debt Instrument [Line Items] |  |
Long-term debt | $ (18) | $ (23)

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + 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 210.5-02.22(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 Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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://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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
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 current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + 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 210.5-02.19,20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtCurrent
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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -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
- Details
Name: | us-gaap_DebtInstrumentAxis=arnc_FivePointSevenTwoPercentNotesDueTwoThousandNineteenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

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

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

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

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

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