Fair Value (Nonrecurring Measurements) (Details)		3 Months Ended				6 Months Ended		9 Months Ended
		Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)		Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)		Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Apr. 12, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Asset Impairment Charges		$ 849,000,000			$ 0			$ 855,000,000	$ 116,000,000
Kilroot and Ballylumford [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					$ 114,000,000				114,000,000
Long Lived Assets Held And Used [Member] | Kilroot and Ballylumford [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1]									$ 232,000,000
Other Asset Impairment Charges	[2]								$ 115,000,000
Long Lived Assets Held And Used [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Asset Impairment Charges			$ 43,000,000			$ 158,000,000
Long Lived Assets Held And Used [Member] | Gener Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Asset Impairment Charges								781,000,000
Long Lived Assets Held And Used [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Asset Impairment Charges								38,000,000
Long Lived Assets Held And Used [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Asset Impairment Charges								30,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		548,000,000						548,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Kilroot and Ballylumford [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring										0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Kilroot and Ballylumford [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring										118,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Kilroot and Ballylumford [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring										$ 0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1]		195,000,000	[3]		272,000,000	[4]
Cumulative Translation Adjustment, Net of Tax, Period Increase (Decrease)						115,000,000		114,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | OPGC [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring			0			0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | OPGC [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring			0			104,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | OPGC [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring			$ 152,000,000			$ 0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Gener Subsidiary [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		1,087,000,000						1,087,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Gener Subsidiary [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Gener Subsidiary [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | Gener Subsidiary [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		306,000,000						306,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		114,000,000						114,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Hawaii | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Hawaii | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Hawaii | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		76,000,000						76,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		44,000,000						44,000,000
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Panama | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Panama | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0						0
Long Lived Assets Held And Used [Member] | Fair Value [Member] | AES Panama | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		14,000,000						$ 14,000,000
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								2.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(2.00%)
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								0.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								40.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								10.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								13.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(25.00%)
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(90.00%)
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(12.00%)
Measurement Input, Discount Rate [Member] | Long Lived Assets Held And Used [Member] | Valuation, Income Approach [Member] | Weighted Average [Member] | OPGC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0.12						$ 0.12
Measurement Input, Discount Rate [Member] | Long Lived Assets Held And Used [Member] | Valuation, Income Approach [Member] | Maximum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0.10						0.10
Measurement Input, Discount Rate [Member] | Long Lived Assets Held And Used [Member] | Valuation, Income Approach [Member] | Maximum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0.13						0.13
Measurement Input, Discount Rate [Member] | Long Lived Assets Held And Used [Member] | Valuation, Income Approach [Member] | Minimum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0.07						0.07
Measurement Input, Discount Rate [Member] | Long Lived Assets Held And Used [Member] | Valuation, Income Approach [Member] | Minimum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0.10						$ 0.10
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(3.00%)
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								29.00%
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								24.00%
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								35.00%
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Gener
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								(94.00%)
Measurement Input, Variable Margin | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Hawaii
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								24.00%
Measurement Input, Sale price per KW | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		315						$ 315
Measurement Input, Sale price per KW | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		520						520
Measurement Input, Sale price per KW | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		$ 160						$ 160
Measurement Input, Age of unit when sold | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								1800.00%
Measurement Input, Age of unit when sold | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								2500.00%
Measurement Input, Age of unit when sold | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum [Member] | AES Panama
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								1500.00%
Interest Rate Contract [Member] | Measurement Input, Entity Credit Risk [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								4.60%
Interest Rate Contract [Member] | Measurement Input, Entity Credit Risk [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								4.70%
Interest Rate Contract [Member] | Measurement Input, Entity Credit Risk [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								3.60%
Cross currency derivatives [Member] | Measurement Input, Entity Credit Risk [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								3.80%
Cross currency derivatives [Member] | Measurement Input, Entity Credit Risk [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								3.80%
Cross currency derivatives [Member] | Measurement Input, Entity Credit Risk [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Inputs, Nonrecurring								3.80%
Foreign Exchange | Weighted Average [Member] | Argentina, Pesos
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Forward Exchange Rate		343						343
Foreign Exchange | Maximum [Member] | Argentina, Pesos
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Forward Exchange Rate		853						853
Foreign Exchange | Minimum [Member] | Argentina, Pesos
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Forward Exchange Rate		79						79

[1] Represents the carrying values at the dates of measurement, before fair value adjustment.

[2] Per the Company’s policy, pre-tax loss is limited to the impairment of long-lived assets. Any additional losses are recognized on completion of the sale. See Note 18—Held-for-Sale and Dispositions for further information.

[3] Excludes $115 million of cumulative translation adjustment (debit balance) in the carrying value.

[4] Includes $114 million of cumulative translation adjustment (debit balance) in the carrying value. Pre-tax loss is limited to the carrying value of the equity method investment excluding CTA.