Contingencies: (Other Litigation) (Details) € in Millions, R$ in Millions, $ in Millions									1 Months Ended	2 Months Ended	6 Months Ended	14 Months Ended
	Mar. 04, 2026 USD ($)	Mar. 04, 2026 BRL (R$)	Mar. 31, 2025 USD ($)	Mar. 31, 2025 BRL (R$)	Dec. 03, 2024 USD ($)	Dec. 03, 2024 BRL (R$)	Sep. 22, 2021 EUR (€)	Sep. 22, 2021 USD ($)	Jul. 31, 2020 defendant	Aug. 31, 2024 patent	Jul. 31, 2025 patent	Dec. 31, 2025 patent	Dec. 18, 2025 claim
Public Prosecutor's Office Of Rome, Italy Vs. Philip Morris Italia S.r.l.
Loss Contingencies [Line Items]
Number of defendants | defendant									3
British American Tobacco p.l.c Vs. Philip Morris Italia S.r.l.
Loss Contingencies [Line Items]
Damages sought							€ 50	$ 59
Brazilian Tax Authority
Loss Contingencies [Line Items]
Damages sought	$ 76	R$ 369	$ 43	R$ 211	$ 28	R$ 137
Future Technology K.K. vs. Sojitz Corporation
Loss Contingencies [Line Items]
Number of patents allegedly infringed | patent										2	8	12
Number of claims withdrawn by plaintiff | claim													1