Contingencies and Commitments - Loss Contingencies (Details) R$ in Millions, $ in Millions	Mar. 31, 2026 USD ($)	Mar. 31, 2026 BRL (R$)	Dec. 31, 2025 USD ($)
Environmental Contingencies
Liability recorded for projected environmental remediation costs	$ 1
Litigation [Member]
Litigation Contingencies
Aggregate reserves for claims deemed both probable and reasonably estimable	14		$ 22
Maximum [Member] \| Litigation [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	171
Maximum [Member] \| Litigation [Member] \| AES Sul [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	11	R$ 60
Maximum [Member] \| Financial Standby Letter of Credit [Member] \| Line of Credit
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	92
Maximum [Member] \| Environmental Remediation [Member] \| AES Sul [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	5
Minimum [Member] \| Litigation [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	98
Minimum [Member] \| Litigation [Member] \| AES Sul [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	3	R$ 15
Minimum [Member] \| Financial Standby Letter of Credit [Member] \| Line of Credit
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	1
Minimum [Member] \| Environmental Remediation [Member] \| AES Sul [Member]
Environmental Contingencies
Loss Contingency, Estimate of Possible Loss	$ 1