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- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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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.

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Segment and Geographic Area Information - Schedule of Operating Results of Arconic's Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Sales	$ 3,472	$ 3,524	$ 3,573	$ 3,445	$ 3,271	$ 3,236	$ 3,261	$ 3,192	$ 14,014	$ 12,960	$ 12,394
Restructuring and other charges									9	165	155
Provision for depreciation and amortization									576	551	1,132
Capital expenditures									715	543
Goodwill	4,500				4,535				4,500	4,535	5,148
Assets	18,693				18,718				18,693	18,718
Total segment sales
Segment Reporting Information [Line Items]
Sales									14,206	13,102	12,513
Segment operating profit									1,581	1,678	1,622
Restructuring and other charges									(84)	154	132
Provision for depreciation and amortization									544	523	504
Assets	15,369				15,321				15,369	15,321
Total segment sales \| Third-Party Sales
Segment Reporting Information [Line Items]
Sales									14,046	12,954	12,395
Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales									160	148	118
Engineered Products and Solutions
Segment Reporting Information [Line Items]
Sales									6,316	5,943	5,728
Capital expenditures									349	308
Goodwill	4,179				4,205				4,179	4,205
Assets	10,346				10,325				10,346	10,325
Engineered Products and Solutions \| Total segment sales
Segment Reporting Information [Line Items]
Sales									6,316	5,943	5,728
Segment operating profit									891	964	955
Restructuring and other charges									71	30	78
Provision for depreciation and amortization									282	268	255
Goodwill	4,179				4,205				4,179	4,205	4,832
Engineered Products and Solutions \| Total segment sales \| Third-Party Sales
Segment Reporting Information [Line Items]
Sales									6,316	5,943	5,728
Engineered Products and Solutions \| Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales									0	0	0
Global Rolled Products
Segment Reporting Information [Line Items]
Sales									5,604	5,000	4,865
Capital expenditures									255	178
Goodwill	245				252				245	252
Assets	3,934				3,955				3,934	3,955
Global Rolled Products \| Total segment sales
Segment Reporting Information [Line Items]
Sales									5,764	5,148	4,983
Segment operating profit									386	424	421
Restructuring and other charges									(156)	72	40
Provision for depreciation and amortization									212	205	201
Goodwill	245				252				245	252	241
Global Rolled Products \| Total segment sales \| Third-Party Sales
Segment Reporting Information [Line Items]
Sales									5,604	5,000	4,865
Global Rolled Products \| Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales									160	148	118
Transportation and Construction Solutions
Segment Reporting Information [Line Items]
Sales									2,126	2,011	1,802
Capital expenditures									111	57
Goodwill	76				78				76	78
Assets	1,089				1,041				1,089	1,041
Transportation and Construction Solutions \| Total segment sales
Segment Reporting Information [Line Items]
Sales									2,126	2,011	1,802
Segment operating profit									304	290	246
Restructuring and other charges									1	52	14
Provision for depreciation and amortization									50	50	48
Goodwill	$ 76				$ 78				76	78	75
Transportation and Construction Solutions \| Total segment sales \| Third-Party Sales
Segment Reporting Information [Line Items]
Sales									2,126	2,011	1,802
Transportation and Construction Solutions \| Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales									$ 0	$ 0	$ 0