Provision for de-characterization of dam structures and asset retirement obligations (Details 2) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2025	Dec. 31, 2024
IfrsStatementLineItems [Line Items]
Other provisions	$ 2,129	$ 1,970
Total other provisions	3,834	3,550
Provision For Decommissioning Restoration And Rehabilitation Costs And Environmental Provisions [Member]
IfrsStatementLineItems [Line Items]
Other provisions	3,834	3,550
Provision For Decommissioning Restoration And Rehabilitation Costs And Environmental Provisions [Member] \| Country Of Brazil [Member]
IfrsStatementLineItems [Line Items]
Other provisions	$ 2,010	$ 1,784
Discount rate	6.95%	7.38%
Cash flow maturity	$ 2,132	$ 2,132
Provision For Decommissioning Restoration And Rehabilitation Costs And Environmental Provisions [Member] \| Country Of Canada [Member]
IfrsStatementLineItems [Line Items]
Other provisions	$ 1,548	$ 1,520
Discount rate	1.59%	1.44%
Cash flow maturity	$ 2,152	$ 2,152
Provision For Decommissioning Restoration And Rehabilitation Costs And Environmental Provisions [Member] \| Country Of Oman [Member]
IfrsStatementLineItems [Line Items]
Other provisions	$ 142	$ 142
Discount rate	3.70%	3.66%
Cash flow maturity	$ 2,035	$ 2,035
Provision For Decommissioning Restoration And Rehabilitation Costs And Environmental Provisions [Member] \| Other Regions [Member]
IfrsStatementLineItems [Line Items]
Other provisions	$ 134	$ 104
Discount rate	2.55%	2.77%
Cash flow maturity
Operating Plants [Member]
IfrsStatementLineItems [Line Items]
Other provisions	2,815	2,509
Closed Plants [Member]
IfrsStatementLineItems [Line Items]
Other provisions	$ 1,019	$ 1,041