Restructuring and Other Charges - Schedule of Restructuring and Related Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Restructuring Cost and Reserve [Line Items]
Total cash charges	$ 1	$ 24	$ 16	$ 89
Total non-cash charges	(1)	1	2	64
Total restructuring and other charges	0	25	18	153
Botlek closure
Restructuring Cost and Reserve [Line Items]
Total cash charges	1	24	9	89
Total non-cash charges	(1)	1	2	64
Total restructuring and other charges	0	25	11	153
Fuzhou closure
Restructuring Cost and Reserve [Line Items]
Total cash charges			7
Total non-cash charges			0
Total restructuring and other charges			7
Severance and employee benefits
Restructuring Cost and Reserve [Line Items]
Total cash charges		8	6	25
Severance and employee benefits \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total cash charges		8	2	25
Severance and employee benefits \| Fuzhou closure
Restructuring Cost and Reserve [Line Items]
Total cash charges			4
Idling Activities
Restructuring Cost and Reserve [Line Items]
Total cash charges	1	16	9	46
Idling Activities \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total cash charges	1	16	6	46
Idling Activities \| Fuzhou closure
Restructuring Cost and Reserve [Line Items]
Total cash charges			3
Asset retirement obligation adjustments
Restructuring Cost and Reserve [Line Items]
Total cash charges				11
Asset retirement obligation adjustments \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total cash charges				11
Contract abandonment and other changes
Restructuring Cost and Reserve [Line Items]
Total cash charges		0	1	7
Contract abandonment and other changes \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total cash charges		0	1	7
Contract abandonment and other changes \| Fuzhou closure
Restructuring Cost and Reserve [Line Items]
Total cash charges			0
Asset disposal
Restructuring Cost and Reserve [Line Items]
Total non-cash charges	(1)	1	2	63
Asset disposal \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total non-cash charges	$ (1)	$ 1	2	63
Asset disposal \| Fuzhou closure
Restructuring Cost and Reserve [Line Items]
Total non-cash charges			$ 0
Other non-cash charges
Restructuring Cost and Reserve [Line Items]
Total non-cash charges				1
Other non-cash charges \| Botlek closure
Restructuring Cost and Reserve [Line Items]
Total non-cash charges				$ 1