Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash Flows from Operating Activities
Net Income/(Loss)	$ (845)	$ (229)
Loss from discontinued operations, net of income tax	(775)	(9)
Loss from continuing operations	(70)	(220)
Adjustments to reconcile net loss to net cash provided by operating activities:
Distributions and equity in earnings of unconsolidated affiliates	26	32
Depreciation and amortization	517	528
Provision for bad debts	18	20
Amortization of nuclear fuel	24	26
Amortization of financing costs and debt discount/premiums	29	29
Adjustment for debt extinguishment	0	14
Amortization of intangibles and out-of-market contracts	51	82
Amortization of unearned equity compensation	16	16
Impairment losses	63	195
Changes in deferred income taxes and liability for uncertain tax benefits	8	1
Changes in nuclear decommissioning trust liability	2	13
Changes in derivative instruments	7	(7)
Changes in collateral posted in support of risk management activities	(189)	323
Proceeds from sale of emission allowances	11	17
Loss on sale of assets	(22)	83
Changes in other working capital	(379)	(272)
Cash provided by continuing operations	112	880
Cash (used) by discontinued operations	(38)	(69)
Net Cash Provided by Operating Activities	74	811
Cash Flows from Investing Activities
Acquisitions of businesses, net of cash acquired	(16)	(17)
Capital expenditures	(542)	(442)
Increase in notes receivable	8	(3)
Purchases of emission allowances	(30)	(27)
Proceeds from sale of emission allowances	59	25
Investments in nuclear decommissioning trust fund securities	(279)	(280)
Proceeds from the sale of nuclear decommissioning trust fund securities	277	267
Proceeds from renewable energy grants and state rebates	8	10
Proceeds from sale of assets, net of cash disposed of	35	25
Investments in unconsolidated affiliates	(30)	1
Other	18	31
Cash (used)/provided by continuing operations	(492)	(410)
Cash used by discontinued operations	(53)	(60)
Net Cash (Used)/Provided by Investing Activities	(545)	(470)
Cash Flows from Financing Activities
Payment of dividends to common and preferred stockholders	(19)	(57)
Payment for preferred shares	0	(226)
Net receipts from settlement of acquired derivatives that include financing elements	2	4
Proceeds from issuance of long-term debt	946	3,223
Payments for short and long-term debt	(530)	(3,505)
Receivable from affiliate	(125)	0
Distributions to, net of contributions from, noncontrolling interest in subsidiaries	14	(21)
Payment of debt issuance costs	(36)	(35)
Other - contingent consideration	(10)	(10)
Cash provided/(used) by continuing operations	242	(627)
Cash used by discontinued operations	(224)	97
Net Cash provided/(used) by Financing Activities	18	(530)
Effect of exchange rate changes on cash and cash equivalents	(8)	(3)
Change in Cash from discontinued operations	(315)	(32)
Net Increase (Decrease) in Cash and Cash Equivalents, Restricted Cash, and Funds Restricted by Counterparties	(146)	(160)
Cash and Cash Equivalents, Funds Deposited by Counterparties and Restricted Cash at Beginning of Period	1,386	1,322
Cash and Cash Equivalents, Funds Deposited by Counterparties and Restricted Cash at End of Period	$ 1,240	$ 1,162