For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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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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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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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 Information - Narrative (Details) $ in Millions		3 Months Ended
Segment Information - Narrative (Details) $ in Millions	Jan. 01, 2020 USD ($)	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020	Dec. 31, 2020 USD ($)	Dec. 31, 2019
Segment Reporting Information [Line Items]
Number of reportable segments \| segment		4
Goodwill		$ 4,086		$ 4,102
Goodwill, impairment loss	$ 0
Revenue Benchmark \| Customer Concentration Risk \| Aerospace
Segment Reporting Information [Line Items]
Concentration risk, percentage		60.00%	73.00%
Revenue Benchmark \| Customer Concentration Risk \| Aerospace \| General Electric Company \| Engine Products
Segment Reporting Information [Line Items]
Concentration risk, percentage		11.00%	13.00%
Engineered Structures
Segment Reporting Information [Line Items]
Goodwill reallocated, increase (decrease)	17
Percentage of fair value in excess of carrying amount			15.00%		60.00%
Engine Products
Segment Reporting Information [Line Items]
Goodwill reallocated, increase (decrease)	$ (17)