Restructuring and Other Credits - Activity and Reserve Balances for Restructuring Charges (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2026	Jun. 30, 2026
Restructuring Reserve [Roll Forward]
Reserve balance at beginning of period	$ 1	$ 1
Restructuring credits		(93)
Other		93
Reserve balance at end of period		1
Disposed by Sale | Disk Forging Facility
Restructuring Cost and Reserve [Line Items]
Gain from disposal of business	93	93
Layoff costs
Restructuring Reserve [Roll Forward]
Reserve balance at beginning of period	1	1
Restructuring credits		0
Other		0
Reserve balance at end of period		1
Other exit costs
Restructuring Reserve [Roll Forward]
Reserve balance at beginning of period	$ 0	0
Restructuring credits		(93)
Other		93
Reserve balance at end of period		$ 0