CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating Revenues
Total operating revenues	$ 484,000,000	$ 532,000,000	$ 1,231,000,000	$ 1,509,000,000
Operating Costs and Expenses
Depreciation and amortization	43,000,000	59,000,000	128,000,000	153,000,000
Impairment losses	0	0	0	59,000,000
Total operating costs and expenses	382,000,000	468,000,000	1,130,000,000	1,409,000,000
Gain on sale of assets	0	262,000,000	0	294,000,000
Operating (Loss)/Income	102,000,000	326,000,000	101,000,000	394,000,000
Other Income/(Expense)
Other income, net	3,000,000	2,000,000	9,000,000	6,000,000
Other expense	0	0	(18,000,000)	0
Total other expense	(1,000,000)	(42,000,000)	(100,000,000)	(126,000,000)
Income Before Reorganization Items and Income Taxes	101,000,000	284,000,000	1,000,000	268,000,000
Reorganization items, net	(29,000,000)	0	48,000,000	0
(Loss)/Income Before Income Taxes	72,000,000	284,000,000	49,000,000	268,000,000
Income tax expense	0	21,000,000	7,000,000	20,000,000
Net (Loss)/Income	72,000,000	263,000,000	42,000,000	248,000,000
GenOn Americas Generation, LLC
Operating Revenues
Total operating revenues	429,000,000	550,000,000	1,080,000,000	1,378,000,000
Operating Costs and Expenses
Depreciation and amortization	18,000,000	21,000,000	54,000,000	59,000,000
Total operating costs and expenses	397,000,000	478,000,000	1,050,000,000	1,264,000,000
Gain on sale of assets	0	74,000,000	0	77,000,000
Operating (Loss)/Income	32,000,000	146,000,000	30,000,000	191,000,000
Other Income/(Expense)
Other income, net	1,000,000	1,000,000	2,000,000	2,000,000
Total other expense		(14,000,000)	(24,000,000)	(42,000,000)
Income Before Reorganization Items and Income Taxes	32,000,000	132,000,000	6,000,000	149,000,000
Reorganization items, net	0	0	42,000,000	0
(Loss)/Income Before Income Taxes	32,000,000	132,000,000	48,000,000	149,000,000
Income tax expense	0	0	0	0
Net (Loss)/Income	32,000,000	132,000,000	48,000,000	149,000,000
GenOn Mid-Atlantic, LLC
Operating Revenues
Total operating revenues	130,000,000	230,000,000	366,000,000	585,000,000
Operating Costs and Expenses
Depreciation and amortization	16,000,000	16,000,000	47,000,000	45,000,000
Total operating costs and expenses	136,000,000	178,000,000	398,000,000	525,000,000
Operating (Loss)/Income	(6,000,000)	52,000,000	(32,000,000)	60,000,000
Other Income/(Expense)
Other income, net	1,000,000	1,000,000	1,000,000	1,000,000
Total other expense	0	(1,000,000)	(1,000,000)	(3,000,000)
(Loss)/Income Before Income Taxes	(6,000,000)	51,000,000	(33,000,000)	57,000,000
Income tax expense	0	0	0	0
Net (Loss)/Income	(6,000,000)	51,000,000	(33,000,000)	57,000,000
Non-affiliated Entity
Operating Revenues
Total operating revenues	483,000,000	544,000,000	1,161,000,000	1,515,000,000
Operating Costs and Expenses
Cost of operations	224,000,000	279,000,000	650,000,000	864,000,000
General and administrative	11,000,000	10,000,000	26,000,000	14,000,000
Other Income/(Expense)
Interest expense	(2,000,000)	(41,000,000)	(83,000,000)	(123,000,000)
Non-affiliated Entity | GenOn Americas Generation, LLC
Operating Revenues
Total operating revenues	402,000,000	494,000,000	1,003,000,000	1,362,000,000
Operating Costs and Expenses
Cost of operations	126,000,000	160,000,000	349,000,000	496,000,000
General and administrative	6,000,000	0	6,000,000	0
Other Income/(Expense)
Interest expense	(1,000,000)	(14,000,000)	(24,000,000)	(39,000,000)
Non-affiliated Entity | GenOn Mid-Atlantic, LLC
Operating Revenues
Total operating revenues	1,000,000	1,000,000	1,000,000	1,000,000
Operating Costs and Expenses
Cost of operations	104,000,000	157,000,000	273,000,000	414,000,000
General and administrative	6,000,000	0	6,000,000	0
Other Income/(Expense)
Interest expense	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Affiliated Entity
Operating Revenues
Total operating revenues	1,000,000	(12,000,000)	70,000,000	(6,000,000)
Operating Costs and Expenses
Cost of operations	90,000,000	74,000,000	226,000,000	180,000,000
General and administrative	14,000,000	46,000,000	100,000,000	139,000,000
Other Income/(Expense)
Interest expense	(2,000,000)	(3,000,000)	(8,000,000)	(9,000,000)
Affiliated Entity | GenOn Americas Generation, LLC
Operating Revenues
Total operating revenues	27,000,000	56,000,000	77,000,000	16,000,000
Operating Costs and Expenses
Cost of operations	238,000,000	276,000,000	588,000,000	647,000,000
General and administrative	9,000,000	21,000,000	53,000,000	62,000,000
Other Income/(Expense)
Interest expense	0	(1,000,000)	(2,000,000)	(5,000,000)
Affiliated Entity | GenOn Mid-Atlantic, LLC
Operating Revenues
Total operating revenues	129,000,000	229,000,000	365,000,000	584,000,000
Operating Costs and Expenses
Cost of operations	6,000,000	(10,000,000)	30,000,000	21,000,000
General and administrative	4,000,000	15,000,000	42,000,000	45,000,000
Other Income/(Expense)
Interest expense	$ 0	$ (1,000,000)	$ (1,000,000)	$ (3,000,000)