Schedule I - Condensed Financial Information of Parent (Statement of Comprehensive Income) (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 Financial Statements, Captions [Line Items]
NET INCOME (LOSS) ATTRIBUTABLE TO THE AES CORPORATION	$ 318	$ (333)	$ (83)	$ 144	$ (78)	$ 210	$ 17	$ 154	$ 46	$ 303	$ 1,203
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, net of income tax (expense) benefit of $(8), $1 and $2, respectively									(52)	(33)	(161)
Reclassification to earnings, net of $0 income tax for all periods									192	23	(21)
Total foreign currency translation adjustments									140	(10)	(182)
Derivative activity:
Change in derivative fair value, net of income tax benefit of $90, $53 and $16, respectively									(368)	(265)	(67)
Reclassification to earnings, net of income tax expense of $19, $4 and $13, respectively									74	42	93
Total change in fair value of derivatives									(294)	(223)	26
Pension activity:
Prior service cost for the period, net of income tax expense of $1, $0 and $1, respectively									(1)	(1)	2
Change in pension adjustments due to net actuarial gain (loss) for the period, net of income tax benefit (expense) of $4, $6 and $(1), respectively									(14)	(23)	(1)
Reclassification of earnings, net of income tax expense of $0, $13 and $2, respectively									0	(28)	(8)
Total pension adjustments									(13)	6	5
OTHER COMPREHENSIVE LOSS									(167)	(227)	(151)
COMPREHENSIVE INCOME (LOSS)									(15)	251	1,414
OCI, Foreign Currency Transaction and Translation Gain (Loss), Arising During Period, Tax									(8)	1	2
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax									0	0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax									(110)	(74)	(27)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax									17	12	24
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax									0	0	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax									(4)	(10)	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax									0	13	2
Parent Company
Condensed Financial Statements, Captions [Line Items]
NET INCOME (LOSS) ATTRIBUTABLE TO THE AES CORPORATION									46	303	1,203
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract]
Foreign currency translation adjustments, net of income tax (expense) benefit of $(8), $1 and $2, respectively									0	(23)	(214)
Reclassification to earnings, net of $0 income tax for all periods									192	23	(21)
Total foreign currency translation adjustments									192	0	(235)
Derivative activity:
Change in derivative fair value, net of income tax benefit of $90, $53 and $16, respectively									(309)	(202)	(64)
Reclassification to earnings, net of income tax expense of $19, $4 and $13, respectively									72	36	78
Total change in fair value of derivatives									(237)	(166)	14
Pension activity:
Prior service cost for the period, net of income tax expense of $1, $0 and $1, respectively									0	1	(2)
Change in pension adjustments due to net actuarial gain (loss) for the period, net of income tax benefit (expense) of $4, $6 and $(1), respectively									(12)	(16)	2
Reclassification of earnings, net of income tax expense of $0, $13 and $2, respectively									0	27	7
Total pension adjustments									(12)	12	7
OTHER COMPREHENSIVE LOSS									(57)	(154)	(214)
COMPREHENSIVE INCOME (LOSS)									(11)	149	989
OCI, Foreign Currency Transaction and Translation Gain (Loss), Arising During Period, Tax									(8)	1	2
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax									0	0	0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax									90	53	16
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax									(19)	(4)	(13)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax									(1)	0	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax									4	6	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax									$ 0	$ (13)	$ (2)