Discontinued Operations and Held for sale businesses (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended				6 Months Ended		12 Months Ended
	Dec. 31, 2017	Nov. 30, 2017	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Mar. 20, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (1,486)		$ (1,659)				$ (1,659)		$ (1,486)
Cash Provided by (Used in) Operating Activities, Discontinued Operations					$ (43)			$ 125
Disposal Group, Including Discontinued Operation, Revenue					862			1,781
Disposal Group, Including Discontinued Operation, Costs of Goods Sold					(823)			(1,697)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			196		0		196	0
Disposal Group, Including Discontinued Operation, Other Expense					(26)			(68)
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax					13			16
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax							238	0
Income (loss) on discontinued operations, before tax, attributable to Noncontrolling interest					(8)			(9)
Income (loss) from discontinued operations, before income tax, attributable to parent					5			7
Discontinued Operation, Tax Effect of Discontinued Operation			(2)		(5)		(2)	(7)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent			194		0		193	0
Disposal Group, Including Discontinued Operation, Assets	2,034								2,034
Disposal Group, Including Discontinued Operation, Liabilities	1,033								1,033
Cash Provided by (Used in) Investing Activities, Discontinued Operations					7			(120)
Proceeds from Divestiture of Businesses and Interests in Affiliates							1,808	33
Gain (Loss) on Disposition of Business			(89)		48		(877)	48
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	1,948								1,948
Disposal Group, Including Discontinued Operation, Liabilities	1,033								1,033
DPL Peaking Generation [Domain] | 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]
Proceeds from Divestiture of Businesses and Interests in Affiliates				$ 239
Gain (Loss) on Disposition of Business				(2)
Compania Transmisora del Norte Grande [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Carrying Amount Disclosure Nonrecurring			95				95
Proceeds from Divestiture of Businesses and Interests in Affiliates			220
Masinloc Subsidiary [Member] | 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]
Proceeds from Divestiture of Businesses and Interests in Affiliates				1,050
Gain (Loss) on Disposition of Business				$ 777
Electrica Santiago (Gener ESSA) [Member] | 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]
Proceeds from Divestiture of Businesses and Interests in Affiliates			307
Gain (Loss) on Disposition of Business			89
Kazakhstan [Member] | 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]
Proceeds from Divestiture of Businesses and Interests in Affiliates					24
Masinloc Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent										51.00%
Eletropaulo Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operations, Investments in and Advances to Affiliates	$ 86								86
Discontinued Operation, Equity Method Investment Retained after Disposal, Ownership Interest Prior to Disposal	17.00%
Deconsolidation, Gain (Loss), Amount		$ (611)
Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses)									(455)
Disposal Group, Including Discontinued Operation, Pension Gains (Losses)									(243)
Eletropaulo Subsidiary [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	$ 86								$ 86
Kazakhstan [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets to be Disposed of			0		0		0	94
Kazakhstan Hydro [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets to be Disposed of			0		$ 90		$ 0	$ 90
Eletropaulo Subsidiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses			340
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			196
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax			$ 238
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Kazakhstan [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Carrying Amount Disclosure Nonrecurring						$ 171
Disposal Group, Including Discontinued Operation, Foreign Currency Translation Gains (Losses)						92
Fair Value Less Costs To Sell						29
Impairment of Long-Lived Assets to be Disposed of						$ 94