Restructuring Activities: (Narrative) (Details) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Jun. 30, 2025 USD ($)	Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Oct. 29, 2024 subsidiary
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4	$ 0		$ 34	$ 243
Number of subsidiaries with proposals for factory closure \| subsidiary						2
Further Integration Program
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4			34
Restructuring charges, expected	$ 50			50
Manufacturing Footprint Optimization, Germany
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 243
Employee Severance \| Further Integration Program
Restructuring Cost and Reserve [Line Items]
Restructuring charges				29
Asset Impairment \| Further Integration Program
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 5
Asset Impairment \| Manufacturing Footprint Optimization, Germany
Restructuring Cost and Reserve [Line Items]
Restructuring charges			92
Pension And Employee Separation Costs \| Manufacturing Footprint Optimization, Germany
Restructuring Cost and Reserve [Line Items]
Restructuring charges			127
Contract Termination and Other Charges \| Manufacturing Footprint Optimization, Germany
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 24