Fair Value (Nonrecurring Unobservable Inputs) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		$ 548
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Assets Liabilities Value		(90)
Laurel Mountain [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					$ 30
Kilroot [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					$ 5
Long Lived Assets Held For Sale [Member] | Level 3 | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring			$ 152	$ 212
Long Lived Assets Held And Used [Member] | Fair Value | AES Panama
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		44
Long Lived Assets Held And Used [Member] | Fair Value | Level 3 | Kilroot [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1]			$ 103
Long Lived Assets Held And Used [Member] | Fair Value | Level 3 | Gener Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		306
Long Lived Assets Held And Used [Member] | Fair Value | Level 3 | AES Panama
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		14
Long Lived Assets Held And Used [Member] | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		103
Long Lived Assets Held And Used [Member] | Level 3 | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		$ 76
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Minimum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		(90.00%)
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Maximum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		10.00%
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Weighted Average | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [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] | Minimum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		(12.00%)
Measurement Input, Long-term Revenue Growth Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [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] | Maximum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [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] | Maximum | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [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] | Weighted Average | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [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] | Weighted Average | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		2.00%
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Minimum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		(94.00%)
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Maximum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		24.00%
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Weighted Average | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		(3.00%)
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		24.00%
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		35.00%
Measurement Input, Operating Margin [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		29.00%
Measurement Input, Discount Rate [Member] | Valuation, Income Approach [Member] | Minimum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		7.00%
Measurement Input, Discount Rate [Member] | Valuation, Income Approach [Member] | Maximum | AES Gener
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		10.00%
Measurement Input, Discount Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Minimum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		10.00%
Measurement Input, Discount Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Maximum | Hawaii Subsidiary [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		13.00%
Measurement Input, Discount Rate [Member] | Valuation, Income Approach [Member] | Long Lived Assets Held And Used [Member] | Weighted Average | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		12.00%
Sale price per kilowatt (USD) | Valuation, Income Approach [Member] | Minimum | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		16000.00%
Sale price per kilowatt (USD) | Valuation, Income Approach [Member] | Maximum | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		52000.00%
Sale price per kilowatt (USD) | Valuation, Income Approach [Member] | Weighted Average | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		31500.00%
Age of unit when sold | Valuation, Income Approach [Member] | Minimum | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		1500.00%
Age of unit when sold | Valuation, Income Approach [Member] | Maximum | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		2500.00%
Age of unit when sold | Valuation, Income Approach [Member] | Weighted Average | Estrella del Mar I
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Fair Value Measurement Inputs, Nonrecurring		1800.00%

[1] See Note 22—Asset Impairment Expense for further information.(3)See Note 8—Investments In and Advances to Affiliates for further information.