Segment Information - Disaggregation of Revenue by Major End Market Served (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	$ 2,703	$ 2,089	$ 7,563	$ 6,084
Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	1,451	1,087	4,077	3,099
Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	630	448	1,690	1,291
Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	295	307	858	919
Forged Wheels
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	327	247	938	775
Aerospace - Commercial
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	1,459	1,109	4,033	3,185
Aerospace - Commercial \| Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	824	591	2,296	1,688
Aerospace - Commercial \| Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	439	310	1,173	882
Aerospace - Commercial \| Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	196	208	564	615
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	391	357	1,146	1,042
Aerospace - Defense \| Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	239	229	727	654
Aerospace - Defense \| Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	73	44	188	130
Aerospace - Defense \| Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	79	84	231	258
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	384	301	1,102	938
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	57	54	164	163
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	327	247	938	775
Gas Turbines
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	349	241	954	678
Gas Turbines \| Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	348	241	953	678
Gas Turbines \| Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	1	0	1	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	120	81	328	241
Other \| Engine Products
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	40	26	101	79
Other \| Fastening Systems
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	60	40	164	116
Other \| Engineered Structures
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Customer, Extent of Reliance [Line Items]
Sales	20	15	63	46
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