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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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Acquisitions and Divestitures (Details) $ in Millions			3 Months Ended						9 Months Ended		12 Months Ended
Acquisitions and Divestitures (Details) $ in Millions	Dec. 01, 2019 USD ($) employee	Aug. 15, 2019 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2020 USD ($)	May 31, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charge (reversal)			$ 0				$ 8		$ 0	$ 442
Restricted cash			$ 3			$ 55			3		$ 55
Engineered Structures \| Small manufacturing facility in the United Kingdom
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, consideration												$ 12
Asset impairment charge (reversal)				$ (7)	$ 12				12
Engineered Structures \| Small Additive Manufacturing Facility Member [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, consideration													$ 1
Asset impairment charge (reversal)								$ 9		9
Loss on sale of business								$ 13		13
Proceeds from the sales of businesses		$ 13
Engine Products \| Forgings Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, consideration	$ 64
Asset impairment charge (reversal)					$ 6				$ 6
Loss on sale of business						3	43				46
Restricted cash						$ 53					$ 53
Sales							$ 30			$ 95
Number of employees \| employee	540