General and Summary of Significant Accounting Policies New Accounting Pronouncements Adopted (Details) - USD ($)		3 Months Ended													12 Months Ended
	Jan. 01, 2020	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	Jan. 01, 2019	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, after Allowance for Credit Loss		$ 101,000,000							$ 109,000,000						$ 101,000,000	$ 109,000,000
Other assets	$ 1,605,000,000	1,660,000,000							1,635,000,000						1,660,000,000	1,635,000,000		$ 1,767,000,000
Operating Lease, Right-of-Use Asset		275,000,000							248,000,000						275,000,000	248,000,000
Revenues		2,560,000,000	$ 2,545,000,000		$ 2,217,000,000		$ 2,338,000,000		2,431,000,000		$ 2,625,000,000	$ 2,483,000,000		$ 2,650,000,000	9,660,000,000	10,189,000,000	$ 10,736,000,000
Cost of Goods and Services Sold															(6,967,000,000)	(7,840,000,000)	(8,163,000,000)
Gross Profit		906,000,000	756,000,000		524,000,000		507,000,000		560,000,000		701,000,000	502,000,000		586,000,000	2,693,000,000	2,349,000,000	2,573,000,000
Interest income															268,000,000	318,000,000	310,000,000
Other Assets, Current	800,000,000	726,000,000							802,000,000						726,000,000	802,000,000
Loan receivable, net of allowance of $0		0							1,351,000,000						0	1,351,000,000
Assets		34,603,000,000							33,648,000,000						34,603,000,000	33,648,000,000	32,521,000,000
Retained Earnings (Accumulated Deficit)	(731,000,000)	(680,000,000)							(692,000,000)						(680,000,000)	(692,000,000)
Cash and Cash Equivalents, at Carrying Value		1,089,000,000							1,029,000,000						1,089,000,000	1,029,000,000
Restricted Cash and Cash Equivalents, Current		297,000,000							336,000,000						297,000,000	336,000,000
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes															(167,000,000)	(227,000,000)	(151,000,000)
Debt service reserves and other deposits		441,000,000							207,000,000						441,000,000	207,000,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		1,827,000,000							1,572,000,000						1,827,000,000	1,572,000,000	2,003,000,000		$ 1,788,000,000
Accumulated Other Comprehensive Income (Loss), Net of Tax		(2,397,000,000)							(2,229,000,000)						(2,397,000,000)	(2,229,000,000)	(2,071,000,000)
Stockholders' Equity Attributable to Noncontrolling Interest	2,217,000,000	2,086,000,000							2,233,000,000						2,086,000,000	2,233,000,000
Liabilities and Equity		34,603,000,000							33,648,000,000						34,603,000,000	33,648,000,000
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest															488,000,000	1,001,000,000	2,018,000,000
Income (Loss) from Continuing Operations, net of Tax		401,000,000	(481,000,000)	[1]	0	[1]	229,000,000	[1]	(120,000,000)	[2]	298,000,000	66,000,000	[2]	233,000,000	149,000,000	477,000,000	1,349,000,000
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		401,000,000	(481,000,000)		3,000,000		229,000,000		(120,000,000)		298,000,000	67,000,000		233,000,000	152,000,000	478,000,000	1,565,000,000
NET INCOME ATTRIBUTABLE TO THE AES CORPORATION		318,000,000	$ (333,000,000)		$ (83,000,000)		$ 144,000,000		(78,000,000)		$ 210,000,000	$ 17,000,000		$ 154,000,000	46,000,000	303,000,000	1,203,000,000
Accrued and other liabilities		1,223,000,000							987,000,000						1,223,000,000	987,000,000		989,000,000
Other long-term liabilities		3,241,000,000							2,917,000,000						3,241,000,000	2,917,000,000		$ 2,949,000,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		527,000,000							580,000,000						527,000,000	580,000,000
Financing Receivable, before Allowance for Credit Loss		110,000,000													110,000,000
Accounts and Financing Receivable, Allowance for Credit Loss	68,000,000	62,000,000													62,000,000
Financing Receivable, Allowance for Credit Loss		9,000,000													9,000,000
Accounts Receivable, Allowance for Credit Loss, Current	20,000,000	13,000,000							20,000,000						13,000,000	20,000,000
Accounts Receivable, Allowance for Credit Loss, Writeoff															(9,000,000)
Accounts Receivable, Allowance for Credit Loss, Recovery															0
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation															(9,000,000)
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)															12,000,000
Allowance for Doubtful Accounts, Premiums and Other Receivables	16,000,000	4,000,000													4,000,000
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, before Allowance for Credit Loss, Current	1,500,000,000
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets									253,000,000							253,000,000
Accrued and other liabilities									27,000,000							27,000,000
Other long-term liabilities									226,000,000							226,000,000
Property, Plant and Equipment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset		3,103,000,000							2,909,000,000						3,103,000,000	2,909,000,000
Accumulated Amortization on PP&E [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset		1,011,000,000							707,000,000						1,011,000,000	707,000,000
Accounts Receivable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, Allowance for Credit Loss, Current	4,000,000	9,000,000													9,000,000
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)															11,000,000
Accounts Receivable, Allowance for Credit Loss, Writeoff															(9,000,000)
Accounts Receivable, Allowance for Credit Loss, Recovery															(3,000,000)
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation															0
Mong Duong Subsidiary [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts and Financing Receivable, Allowance for Credit Loss		32,000,000													32,000,000
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation															0
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)															0
Financing Receivable, Allowance for Credit Loss, Writeoff															0
Financing Receivable, Allowance for Credit Loss, Recovery															(2,000,000)
Mong Duong Subsidiary [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,400,000,000
Financing Receivable, Credit Loss Rate	2.40%
Accounts and Financing Receivable, Allowance for Credit Loss	$ 34,000,000
AES Argentina [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss		20,000,000													20,000,000
Accounts Receivable, Allowance for Credit Loss, Recovery															(1,000,000)
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation															(9,000,000)
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)															1,000,000
Financing Receivable, Allowance for Credit Loss, Writeoff															0
AES Argentina [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Credit Loss Rate	41.20%
Financing Receivable, Allowance for Credit Loss	$ 29,000,000
Gener Subsidiary [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets																	1,514,000,000
Accrued and other liabilities																	962,000,000
Other long-term liabilities																	2,723,000,000
Financing Receivable, before Allowance for Credit Loss									33,000,000							33,000,000
Other Entity [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)															0
Accounts Receivable, Allowance for Credit Loss, Writeoff															0
Accounts Receivable, Allowance for Credit Loss, Recovery															0
Financing Receivable, Allowance for Credit Loss, Foreign Currency Translation															0
Accounts Receivable, Allowance for Credit Loss, Noncurrent	1,000,000	1,000,000													1,000,000
Debt Securities [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 326,000,000
ARGENTINA
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, after Allowance for Credit Loss		39,000,000							$ 64,000,000						39,000,000	64,000,000
Revenues															308,000,000	$ 373,000,000	$ 487,000,000
Financing Receivable, before Allowance for Credit Loss		48,000,000													48,000,000
Financing Receivable, Allowance for Credit Loss		$ 9,000,000													$ 9,000,000

[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).