Fair Value (Nonrecurring Measurements) (Details) - USD ($)		3 Months Ended					9 Months Ended	12 Months Ended
		Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2019	Apr. 12, 2019	Oct. 01, 2018
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges		$ 849,000,000			$ 69,000,000	$ 116,000,000		$ 864,000,000	$ 185,000,000	$ 208,000,000
Other non-operating expense								202,000,000	92,000,000	147,000,000
Shady Point [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring										30,000,000
Nejapa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring										$ 5,000,000
Guacolda Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Equity Method Investment, Other than Temporary Impairment									92,000,000
Kilroot and Ballylumford [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					114,000,000				114,000,000
OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Equity Method Investment, Other than Temporary Impairment			$ 158,000,000	$ 43,000,000	92,000,000			201,000,000
Estimate of Fair Value Measurement [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								548,000,000
Equity Method Investments [Member] | Reported Value Measurement [Member] | Guacolda Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1]												$ 304,000,000
Long Lived Assets Held And Used [Member] | Nejapa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges	[2]								60,000,000
Long Lived Assets Held And Used [Member] | Kilroot and Ballylumford [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges	[3]								115,000,000
Assets Carrying Amount Disclosure Nonrecurring												$ 232,000,000
Long Lived Assets Held And Used [Member] | US Generation Facility [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges	[2]							781,000,000
Long Lived Assets Held And Used [Member] | AES Panama
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges								30,000,000
Long Lived Assets Held And Used [Member] | AES Hawaii
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges								38,000,000
Long Lived Assets Held And Used [Member] | OPGC
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Other Asset Impairment Charges							$ 158,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Nejapa [Member] | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]										$ 0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Nejapa [Member] | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]										$ 0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Nejapa [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]				103,000,000				103,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Panama
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								44,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Panama | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Panama | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Panama | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								14,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Hawaii
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								114,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Hawaii | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Hawaii | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | AES Hawaii | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								76,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | OPGC
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		272,000,000					272,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | OPGC | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		0					0
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | OPGC | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		104,000,000					104,000,000
Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | OPGC | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		$ 0					$ 0
Long Lived Assets Held And Used [Member] | Reported Value Measurement [Member] | Nejapa [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1],[2]				163,000,000				163,000,000
Long Lived Assets Held For Sale [Member] | Guacolda Affiliate [Member] | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					0				0
Long Lived Assets Held For Sale [Member] | Guacolda Affiliate [Member] | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					0				0
Long Lived Assets Held For Sale [Member] | Guacolda Affiliate [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring					212,000,000				212,000,000
Long Lived Assets Held For Sale [Member] | OPGC Affiliate [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring				$ 152,000,000	212,000,000				212,000,000
Long Lived Assets Held For Sale [Member] | Estimate of Fair Value Measurement [Member] | OPGC Affiliate [Member] | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held For Sale [Member] | Estimate of Fair Value Measurement [Member] | OPGC Affiliate [Member] | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring								0
Long Lived Assets Held For Sale [Member] | Reported Value Measurement [Member] | OPGC Affiliate [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1]							195,000,000
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Kilroot and Ballylumford [Member] | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[3]				0				0
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Kilroot and Ballylumford [Member] | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[3]							118,000,000
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | Kilroot and Ballylumford [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[3]							0
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | US Generation Facility [Member] | Level 1
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]							0
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | US Generation Facility [Member] | Level 2
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]							0
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Estimate of Fair Value Measurement [Member] | US Generation Facility [Member] | Level 3
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[2]							306,000,000
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Reported Value Measurement [Member] | Kilroot and Ballylumford [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1],[3]				$ 232,000,000				$ 232,000,000
Fair Value, Nonrecurring [Member] | Long Lived Assets Held And Used [Member] | Reported Value Measurement [Member] | US Generation Facility [Member]
Fair Value Assets Measured On Nonrecurring Basis Unobservable Inputs [Line Items]
Assets Carrying Amount Disclosure Nonrecurring	[1],[2]							$ 1,087,000,000

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

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

[3] Per the Company's policy, pre-tax loss is limited to the impairment of long-lived assets. Any additional loss will be recognized on completion of the sale. See Note 22—Asset Impairment Expense and Note 25—Held-for-Sale and Dispositions for further information.