CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 294	$ 563
Funds deposited by counterparties	31	33
Restricted cash	11	17
Accounts receivable, net	1,049	1,024
Inventory	370	412
Derivative instruments	850	764
Cash collateral paid in support of energy risk management activities	163	287
Prepayments and other current assets	277	302
Current assets - held-for-sale	0	1
Current assets - discontinued operations	0	197
Total current assets	3,045	3,600
Property, plant and equipment, net	2,610	3,048
Other Assets
Equity investments in affiliates	383	412
Operating lease right-of-use assets, net	499
Goodwill	573	573
Intangible assets, net	561	591
Nuclear decommissioning trust fund	748	663
Derivative instruments	426	317
Deferred income taxes	55	46
Other non-current assets	271	289
Non-current assets - held-for-sale	0	77
Non-current assets - discontinued operations	0	1,012
Total other assets	3,516	3,980
Total Assets	9,171	10,628
Current Liabilities
Current portion of long-term debt and capital leases	87	72
Current portion of operating lease liabilities	74
Accounts payable	723	863
Derivative instruments	778	673
Cash collateral received in support of energy risk management activities	31	33
Accrued expenses and other current liabilities	601	680
Current liabilities - held-for-sale	0	5
Current liabilities - discontinued operations	0	72
Total current liabilities	2,294	2,398
Other Liabilities
Long-term debt and capital leases	5,794	6,449
Non-current operating lease liabilities	513
Nuclear decommissioning reserve	290	282
Nuclear decommissioning trust liability	448	371
Derivative instruments	374	304
Deferred income taxes	71	65
Other non-current liabilities	1,016	1,274
Non-current liabilities - held-for-sale	0	65
Non-current liabilities - discontinued operations	0	635
Total other liabilities	8,506	9,445
Total Liabilities	10,800	11,843
Redeemable noncontrolling interest in subsidiaries	19	19
Commitments and Contingencies
Stockholders' Equity
Common stock; $0.01 par value; 500,000,000 shares authorized; 421,830,474 and 420,288,886 shares issued and 258,570,598 and 283,650,039 shares outstanding at June 30, 2019 and December 31, 2018, respectively	4	4
Additional paid-in-capital	8,488	8,510
Accumulated deficit	(5,355)	(6,022)
Less treasury stock, at cost - 163,259,876 and 136,638,847 shares at June 30, 2019 and December 31, 2018, respectively	(4,686)	(3,632)
Accumulated other comprehensive loss	(99)	(94)
Total Stockholders' Equity	(1,648)	(1,234)
Total Liabilities and Stockholders' Equity	$ 9,171	$ 10,628