Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosures [Line Items]
Effective Income Tax Rate Reconciliation, Percent	89.00%	28.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Income Tax Expense (Benefit)	$ 8	$ 89
Gener Subsidiary [Member]
Income Tax Disclosures [Line Items]
Income Tax Expense (Benefit)	$ 0
AES Mexico [Member]
Income Tax Disclosures [Line Items]
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation		$ 19