CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 243	$ 563
Funds deposited by counterparties	30	33
Restricted cash	4	17
Accounts receivable, net	1,376	1,024
Inventory	364	412
Derivative instruments	735	764
Cash collateral paid in support of energy risk management activities	164	287
Prepayments and other current assets	271	302
Current assets - held-for-sale	0	1
Current assets - discontinued operations	0	197
Total current assets	3,187	3,600
Property, plant and equipment, net	2,615	3,048
Other Assets
Equity investments in affiliates	405	412
Operating lease right-of-use assets, net	482
Goodwill	591	573
Intangible assets, net	828	591
Nuclear decommissioning trust fund	756	663
Derivative instruments	358	317
Deferred income taxes	53	46
Other non-current assets	252	289
Non-current assets - held-for-sale	0	77
Non-current assets - discontinued operations	0	1,012
Total other assets	3,725	3,980
Total Assets	9,527	10,628
Current Liabilities
Current portion of long-term debt	302	72
Current portion of operating lease liabilities	73
Accounts payable	866	863
Derivative instruments	668	673
Cash collateral received in support of energy risk management activities	30	33
Accrued expenses and other current liabilities	625	680
Current liabilities - held-for-sale	0	5
Current liabilities - discontinued operations	0	72
Total current liabilities	2,564	2,398
Other Liabilities
Long-term debt	5,798	6,449
Non-current operating lease liabilities	500
Nuclear decommissioning reserve	294	282
Nuclear decommissioning trust liability	453	371
Derivative instruments	364	304
Deferred income taxes	70	65
Other non-current liabilities	1,036	1,274
Non-current liabilities - held-for-sale	0	65
Non-current liabilities - discontinued operations	0	635
Total other liabilities	8,515	9,445
Total Liabilities	11,079	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; 421,859,844 and 420,288,886 shares issued and 251,985,517 and 283,650,039 shares outstanding at September 30, 2019 and December 31, 2018, respectively	4	4
Additional paid-in-capital	8,494	8,510
Accumulated deficit	(4,991)	(6,022)
Less treasury stock, at cost - 169,874,327 and 136,638,847 shares at September 30, 2019 and December 31, 2018, respectively	(4,920)	(3,632)
Accumulated other comprehensive loss	(158)	(94)
Total Stockholders' Equity	(1,571)	(1,234)
Total Liabilities and Stockholders' Equity	$ 9,527	$ 10,628
Common stock, par or value (in usd per share)	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	421,859,844	420,288,886
Treasury stock, shares (in shares)	169,874,327	136,638,847
Common stock, shares outstanding (in shares)	251,985,517	283,650,039