Schedule I - Condensed Financial Information of Parent Schedule I - Condensed Financial Information of Parent (Statement of Operations) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements, Captions [Line Items]
Interest income									$ 268	$ 318	$ 310
General and administrative expenses									(165)	(196)	(192)
Other expense									(53)	(80)	(58)
Gain (Loss) on Extinguishment of Debt									(186)	(169)	(188)
Interest expense									(1,038)	(1,050)	(1,056)
Income (loss) before income taxes									(192)	(277)	(509)
Income tax benefit (expense)									(216)	(352)	(708)
NET INCOME (LOSS) ATTRIBUTABLE TO THE AES CORPORATION	$ 318	$ (333)	$ (83)	$ 144	$ (78)	$ 210	$ 17	$ 154	46	303	1,203
Parent Company
Condensed Income Statements, Captions [Line Items]
Revenue from subsidiaries and affiliates									29	30	36
Equity in earnings of subsidiaries and affiliates									383	674	1,909
Interest income									31	53	39
General and administrative expenses									(125)	(148)	(142)
Other income									26	1	25
Other expense									(6)	(103)	0
Gain (Loss) on Extinguishment of Debt									(146)	(5)	(171)
Interest expense									(163)	(197)	(220)
Income (loss) before income taxes									29	305	1,476
Income tax benefit (expense)									17	(2)	(273)
NET INCOME (LOSS) ATTRIBUTABLE TO THE AES CORPORATION									$ 46	$ 303	$ 1,203