Restructuring Activities: (Narrative) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Oct. 29, 2024 subsidiary
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			$ 241	$ 180	$ 109
Number of subsidiaries with proposals for factory closure | subsidiary						2
Reclassification of accumulated foreign currency translation losses from other comprehensive losses			0	(38)	0
Contract Termination And Other Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			24	77	78
Asset Impairment
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			92	65	$ 31
Manufacturing Footprint Optimization, Germany
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			241
Manufacturing Footprint Optimization, Germany | Pension And Employee Separation Costs
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			125
Manufacturing Footprint Optimization, Germany | Contract Termination And Other Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			24
Manufacturing Footprint Optimization, Germany | Asset Impairment
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs			$ 92
US Restructuring
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs				133
US Restructuring | Contract Termination And Other Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs				73
US Restructuring | Asset Impairment
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs				60
US Restructuring | Pre Paid Commitments
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs				$ 20
Venezuela Plan
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs	$ 47
Reclassification of accumulated foreign currency translation losses from other comprehensive losses	38
Venezuela Plan | Contract Termination And Other Charges
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs	4
Venezuela Plan | Asset Impairment
Restructuring Cost and Reserve [Line Items]
Pre-tax asset impairment and exit costs	$ 5
e-Vapor Products Manufacturing Optimization
Restructuring Cost and Reserve [Line Items]
Exit costs		$ 109
e-Vapor Products Manufacturing Optimization | Contract Termination And Other Charges
Restructuring Cost and Reserve [Line Items]
Exit costs		78
e-Vapor Products Manufacturing Optimization | Asset Impairment
Restructuring Cost and Reserve [Line Items]
Exit costs		31
e-Vapor Products Manufacturing Optimization | Finance Lease Termination
Restructuring Cost and Reserve [Line Items]
Exit costs		$ 21