Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ 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
Gain (Loss) on Disposition of Business														$ (95)	$ 28	$ 984
Other Asset Impairment Charges		$ 849						$ 69			$ 116			864	185	208
Revenues	$ 2,560	2,545		$ 2,217		$ 2,338		2,431		$ 2,625	2,483		$ 2,650	9,660	10,189	10,736
Net equity in earnings (losses) of affiliates		(112)						(175)						(123)	(172)	39
Selected Quarterly Financial Information [Abstract]
Operating margin	906	756		524		507		560		701	502		586	2,693	2,349	2,573
Income (Loss) from Continuing Operations, net of Tax	401	(481)	[1]	0	[1]	229	[1]	(120)	[2]	298	66	[2]	233	149	477	1,349
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	0	0		3		0		0		0	1		0
NET INCOME (LOSS)	401	(481)		3		229		(120)		298	67		233	152	478	1,565
Net income (loss) attributable to The AES Corporation	$ 318	$ (333)		$ (83)		$ 144		$ (78)		$ 210	$ 17		$ 154	$ 46	$ 303	$ 1,203
Basic earnings (loss) per share:
Income (loss) from continuing operations attributable to The AES Corporation common stockholders, net of tax	$ 0.48	$ (0.50)		$ (0.13)		$ 0.22		$ (0.12)		$ 0.32	$ 0.02		$ 0.23	$ 0.06	$ 0.46	$ 1.49
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0	0		0.01		0		0		0	0		0	0.01	0	0.33
NET INCOME ATTRIBUTABLE TO THE AES CORPORATION COMMON STOCKHOLDERS	0.48	(0.50)		(0.12)		0.22		(0.12)		0.32	0.02		0.23	0.07	0.46	1.82
Diluted earnings (loss) per share:
Income (loss) from continuing operations attributable to The AES Corporation common stockholders, net of tax	0.47	(0.50)		(0.13)		0.22		(0.12)		0.32	0.02		0.23	0.06	0.45	1.48
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0	0		0.01		0		0		0	0		0	0.01	0	0.33
Earnings Per Share, Diluted	0.47	(0.50)		(0.12)		0.22		(0.12)		0.32	0.02		0.23	0.07	0.45	1.81
Dividends declared per common share	$ 0.29	$ 0.14		$ 0		$ 0.14		$ 0.28		$ 0.14	$ 0		$ 0.14	$ 0.5804	$ 0.5528	$ 0.53
OPGC Affiliate [Member]
Gain (Loss) on Disposition of Business	$ 23
Equity Method Investment, Other than Temporary Impairment				$ 158		$ 43		$ 92						$ 201
Guacolda Affiliate [Member]
Equity Method Investment, Other than Temporary Impairment															$ 92
UNITED STATES
Tax Cuts and Jobs Act, Income Tax Expense (Benefit)															194
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)															$ (77)

[1] Includes pre-tax impairment expense of $849 million in the third quarter of 2020 (See Note 22—Asset Impairment Expense), other-than-temporary impairment of OPGC of $43 million and $158 million in the first and second quarters of 2020, respectively, and net equity in losses of affiliates, primarily at Guacolda, of $112 million in the third quarter of 2020 (See Note 8—Investments in and Advances to Affiliates).

[2] Includes pre-tax impairment expense of $116 million and $69 million in the second and fourth quarters of 2019, respectively (See Note 22—Asset Impairment Expense), other-than-temporary impairment of OPGC of $92 million, and net equity in losses of affiliates, primarily at Guacolda, of $175 million in the fourth quarter of 2019 (See Note 8—Investments in and Advances to Affiliates).