Asset Impairment Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 168	$ 159
Kazakhstan [Member]
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use	94	0
buffalo gap II [Member] [Member]
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use	0	159
DPL Subsidiary [Member]
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use	66	0
Energy Storage [Member]
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use	8	0
Parent Company [Member]
Asset Impairment Expense [Line Items]
Impairment of Long-Lived Assets Held-for-use		49
Long Lived Assets Held And Used [Member] | Stuart Station [Member]
Asset Impairment Expense [Line Items]
Assets, fair value	3
Long Lived Assets Held And Used [Member] | Killen Station [Member]
Asset Impairment Expense [Line Items]
Assets, fair value	$ 8
Long Lived Assets Held And Used [Member] | buffalo gap II [Member] [Member]
Asset Impairment Expense [Line Items]
Assets, fair value		$ 92