Segment Information - Disaggregation of Revenue by Major End Market Served (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	$ 2,547	$ 2,053	$ 4,860	$ 3,995
Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	1,373	1,038	2,626	2,012
Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	589	431	1,060	843
Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	269	308	563	612
Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	316	276	611	528
Aerospace - Commercial
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	1,359	1,060	2,574	2,076
Aerospace - Commercial | Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	770	562	1,472	1,097
Aerospace - Commercial | Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	412	297	734	572
Aerospace - Commercial | Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	177	201	368	407
Aerospace - Commercial | Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Aerospace - Defense
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	389	352	755	685
Aerospace - Defense | Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	250	214	488	425
Aerospace - Defense | Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	64	44	115	86
Aerospace - Defense | Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	75	94	152	174
Aerospace - Defense | Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Commercial Transportation
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	372	332	718	637
Commercial Transportation | Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Commercial Transportation | Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	56	56	107	109
Commercial Transportation | Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Commercial Transportation | Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	316	276	611	528
Gas Turbines
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	321	233	605	437
Gas Turbines | Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	321	233	605	437
Gas Turbines | Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Gas Turbines | Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Gas Turbines | Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	0	0	0	0
Other
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	106	76	208	160
Other | Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	32	29	61	53
Other | Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	57	34	104	76
Other | Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	17	13	43	31
Other | Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	$ 0	$ 0	$ 0	$ 0