XML 73 R97.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Earnings Per Share - Additional Information (Details) - shares | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2017 | Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Common stock outstanding (in shares) | 432,855,183 |  | 483,000,000
Incremental Common Shares Attributable to Dilutive Effect of Accelerated Share Repurchase Agreements | 55,000,000 |  |
Mandatory convertible preferred stock |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Shares that would have been included in diluted earnings per share calculation (in shares) |  | 30,000,000 |
Convertible notes |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Shares that would have been included in diluted earnings per share calculation (in shares) |  | 14,000,000 |
Stock Options |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Shares that would have been included in diluted earnings per share calculation (in shares) |  | 1,000,000 |
Stock awards |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |
Shares that would have been included in diluted earnings per share calculation (in shares) |  | 5,000,000 |

X
- Definition Shares that would have been included in diluted earnings per share calculation. + References No definition available. + Details
Name: | arnc_SharesThatWouldHaveBeenIncludedInDilutedEarningsPerShareCalculation
Namespace Prefix: | arnc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of accelerated share repurchase agreements. An accelerated share repurchase program is a combination of transactions that permits an entity to purchase a targeted number of shares immediately with the final purchase price of those shares determined by an average market price over a fixed period of time. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=117326831&loc=d3e1707-109256 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6405686&loc=d3e22802-112653 + Details
Name: | us-gaap_IncrementalCommonSharesAttributableToAcceleratedShareRepurchaseAgreements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=arnc_MandatoryConvertibleNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=arnc_ConvertibleNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=arnc_StockAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |