Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 1,659	$ 1,518
Funds deposited by counterparties	101	106
Restricted cash	387	414
Accounts receivable — trade, less allowance for doubtful accounts of $19 and $21	1,018	1,157
Inventory	1,161	1,252
Derivative instruments	2,113	1,915
Cash collateral paid in support of energy risk management activities	411	568
Renewable energy grant receivable, net	35	13
Disposal Group, Including Discontinued Operation, Other Assets, Current	0	6
Prepayments and other current assets	461	442
Total current assets	7,346	7,391
Property, plant and equipment, net of accumulated depreciation of $7,093 and $6,804	18,763	18,732
Other Assets
Equity investments in affiliates	898	1,045
Notes receivable, less current portion	40	53
Goodwill	999	999
Intangible assets, net of accumulated amortization of $1,592 and $1,525	2,256	2,310
Nuclear decommissioning trust fund	577	561
Derivative instruments	465	305
Deferred income taxes	185	167
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	0	105
Other non-current assets	1,151	1,214
Total other assets	6,571	6,759
Total Assets	32,680	32,882
Current Liabilities
Current portion of long-term debt and capital leases	465	481
Accounts payable	845	869
Derivative instruments	1,947	1,721
Cash collateral received in support of energy risk management activities	100	106
Disposal Group, Including Discontinued Operation, Liabilities, Current	0	2
Accrued expenses and other current liabilities	981	1,196
Total current liabilities	4,338	4,375
Other Liabilities
Long-term debt and capital leases	18,677	18,983
Nuclear decommissioning reserve	330	326
Nuclear decommissioning trust liability	294	283
Deferred income taxes	37	19
Derivative instruments	627	493
Off-market Lease, Unfavorable	1,122	1,146
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	4
Other non-current liabilities	1,547	1,488
Total non-current liabilities	22,634	22,742
Total Liabilities	26,972	27,117
2.822% convertible perpetual preferred stock	304	302
Redeemable noncontrolling interest in subsidiaries	23	29
Stockholders’ Equity
Common stock	4	4
Additional paid-in capital	8,299	8,296
Retained deficit	(2,977)	(3,007)
Less treasury stock, at cost — 102,450,781 and 102,749,908 shares, respectively	(2,406)	(2,413)
Accumulated other comprehensive loss	(195)	(173)
Noncontrolling interest	2,656	2,727
Total Stockholders’ Equity	5,381	5,434
Total Liabilities and Stockholders’ Equity	$ 32,680	$ 32,882