Acquisitions and Dispositions (Details) - USD ($)		12 Months Ended
	May 22, 2019	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2021
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Business Combination, Consideration Transferred		$ 28,000,000
Gain (Loss) on Disposition of Business		(1,683,000,000)		$ (95,000,000)		$ 28,000,000
Proceeds from Divestiture of Businesses and Interests in Affiliates		95,000,000		169,000,000		178,000,000
Income (Loss) from Continuing Operations Attributable to Parent		413,000,000		(43,000,000)		(302,000,000)
Dispositions and Held-for-Sales Businesses
Asset Retirement Obligation, Revision of Estimate		13,000,000		3,000,000
Goodwill, Written off Related to Sale of Business Unit		224,000,000
Goodwill		1,177,000,000		$ 1,061,000,000
JORDAN
Dispositions and Held-for-Sales Businesses
Equity Method Investment, Ownership Percentage				10.00%
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		77,000,000		$ 75,000,000		52,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Mong Duong Subsidiary [Member]
Dispositions and Held-for-Sales Businesses
Disposal Group Not Discontinued Operation Ownership Interest Sold				51.00%
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Mong Duong Finance Holdings B.V._Related Party [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		56,000,000		$ 55,000,000		34,000,000
Dispositions and Held-for-Sales Businesses
Disposal Group Not Discontinued Operation Ownership Interest Sold				51.00%
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Mong Duong held-dfor-sale [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Assets Carrying Amount Disclosure Nonrecurring		501,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | JORDAN
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		21,000,000		$ 20,000,000		18,000,000
Assets Carrying Amount Disclosure Nonrecurring		175,000,000
Proceeds from Divestiture of Businesses				$ 58,000,000
Dispositions and Held-for-Sales Businesses
Disposal Group Not Discontinued Operation Ownership Interest Sold				26.00%
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		40,000,000		$ 57,000,000		80,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Kilroot and Ballylumford [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Business						33,000,000
Proceeds from Divestiture of Businesses and Interests in Affiliates						118,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | DPL Subsidiary [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		0	[1]	0	[1]	52,000,000
Asset Retirement Obligation, Cash Paid to Settle						51,000,000
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal						20,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Shady Point [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		0		0		(5,000,000)
Proceeds from Divestiture of Businesses and Interests in Affiliates	$ 29,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Redondo Beach [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Assets Carrying Amount Disclosure Nonrecurring				24,000,000
Dispositions and Held-for-Sales Businesses
Gain (Loss) on Disposition of Assets				41,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Kazakhstan Hydro [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses and Interests in Affiliates							$ 75,000,000
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal				(30,000,000)
Proceeds from Legal Settlements				45,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Other Subsidiaries [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		0		0		(3,000,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Itabo Disposal Group
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		5,000,000		41,000,000		30,000,000
Proceeds from Divestiture of Businesses and Interests in Affiliates		$ 88,000,000
Dispositions and Held-for-Sales Businesses
Disposal Group Not Discontinued Operation Ownership Interest Sold		43.00%
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Estrella del Mar I
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		$ 0		5,000,000		12,000,000
Proceeds from Divestiture of Businesses and Interests in Affiliates		6,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Uruguaiana [Member]
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal				(95,000,000)
Guaranty Liabilities				22,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Alto Maipo
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, Attributable to Parent, before Income Tax		35,000,000		$ 11,000,000		$ (6,000,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | AES Tiete Inova Solucoes
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses and Interests in Affiliates		20,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Colon [Domain]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses and Interests in Affiliates		51,000,000
Kazakhstan Hydro [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Dispositions and Held-for-Sales Businesses
Disposal Group Not Discontinued Operation Ownership Interest Sold							100.00%
Itabo Disposal Group | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal		4,000,000
AES Tiete Inova Solucoes | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal		(1,000,000)
Alto Maipo
Dispositions and Held-for-Sales Businesses
Goodwill								$ 868,000,000
Alto Maipo | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal		2,074,000,000
Goodwill, Written off Related to Sale of Business Unit		224,000,000
Colon [Domain] | Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Dispositions and Held-for-Sales Businesses
Pre-tax gain on disposal		$ 6,000,000

[1] After the retirement of Stuart and Killen in 2018, the Company entered into contracts to buy back all open capacity years for the plants at prices lower than the PJM capacity revenue prices. As such, the Company continued to earn capacity margin until the plants were transferred in December 2019.