Consolidated Statements of Cash Flows (FirstEnergy Solutions Corp.) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 771	$ 869	$ 718
Adjustments to reconcile net income to net cash from operating activities-
Provision for depreciation	1,124	1,066	750
Nuclear fuel and lease amortization	210	201	168
Deferred rents and lease market valuation liability	(104)	(49)	(54)
Deferred income taxes and investment tax credits, net	647	798	450
Impairments of long-lived assets	0	413	388
Investments impairments	27	19	33
Pensions and OPEB mark-to-market adjustment	609	507	190
Accrued compensation and retirement benefits	(55)	69	21
Pension trust contribution	(600)	(372)	0
Gain on sales of investment securities held in trusts	(71)	(59)	(55)
Commodity derivative transactions, net	(95)	(27)	(81)
Cash collateral, net	16	(79)	(26)
Decrease (increase) in operating assets-
Receivables	(13)	147	(177)
Materials and supplies	(50)	14	2
Prepayments and other current assets	(12)	101	100
Increase (decrease) in operating liabilities-
Accounts payable	71	35	43
Accrued taxes	6	91	57
Other	98	(79)	15
Net cash provided from operating activities	2,320	3,063	3,076
New financing-
Long-term debt	750	604	1,099
Short-term borrowings, net	1,969	0	0
Redemptions and Repayments-
Long-term debt	(940)	(1,909)	(1,015)
Short-term borrowings, net	0	(700)	(378)
Other	(52)	(38)	(19)
Net cash provided from (used for) financing activities	807	(2,924)	(983)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(2,678)	(2,129)	(1,780)
Nuclear fuel	(286)	(149)	(183)
Proceeds from asset sales	17	840	117
Sales of investment securities held in trusts	2,980	4,207	3,172
Purchases of investment securities held in trusts	(3,020)	(4,309)	(3,219)
Customer acquisition costs	(2)	(3)	(113)
Other	(41)	51	27
Net cash used for investing activities	(3,157)	(956)	(1,948)
Net change in cash and cash equivalents	(30)	(817)	145
Cash and cash equivalents at beginning of period	202	1,019	874
Cash and cash equivalents at end of period	172	202	1,019
Cash paid (received) during the year-
Interest (net of amounts capitalized)	962	935	662
Income taxes	(6)	(358)	(42)
FES
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	187	(59)	231
Adjustments to reconcile net income to net cash from operating activities-
Provision for depreciation	276	275	246
Nuclear fuel and lease amortization	210	200	172
Deferred rents and lease market valuation liability	(100)	(42)	(47)
Deferred income taxes and investment tax credits, net	214	199	150
Impairments of long-lived assets	0	294	388
Investments impairments	14	17	32
Pensions and OPEB mark-to-market adjustment	166	171	107
Accrued compensation and retirement benefits	1	(41)	(25)
Pension trust contribution	(209)	0	0
Gain on sales of investment securities held in trusts	(65)	(50)	(51)
Gain on asset sales	(17)	0	(2)
Commodity derivative transactions, net	(74)	(68)	(81)
Cash collateral, net	(33)	(88)	(7)
Decrease (increase) in operating assets-
Receivables	135	(126)	(362)
Materials and supplies	(13)	16	(11)
Prepayments and other current assets	(18)	22	42
Increase (decrease) in operating liabilities-
Accounts payable	214	(54)	(27)
Accrued taxes	(56)	159	2
Other	(11)	(6)	29
Net cash provided from operating activities	821	819	786
New financing-
Long-term debt	650	247	715
Short-term borrowings, net	3	(11)	2
Redemptions and Repayments-
Long-term debt	(429)	(856)	(772)
Short-term borrowings, net	0	0	0
Other	(12)	(11)	(2)
Net cash provided from (used for) financing activities	212	(631)	(57)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(795)	(600)	(852)
Nuclear fuel	(286)	(149)	(183)
Proceeds from asset sales	17	599	117
Sales of investment securities held in trusts	1,464	1,843	1,927
Purchases of investment securities held in trusts	(1,502)	(1,890)	(1,974)
Loans to affiliated companies, net	107	14	408
Customer acquisition costs	(2)	(3)	(113)
Leasehold improvement payments to affiliated companies	0	0	(51)
Other	(40)	(4)	1
Net cash used for investing activities	(1,037)	(190)	(720)
Net change in cash and cash equivalents	(4)	(2)	9
Cash and cash equivalents at beginning of period	7	9	0
Cash and cash equivalents at end of period	3	7	9
Cash paid (received) during the year-
Interest (net of amounts capitalized)	174	167	117
Income taxes	$ 72	$ (387)	$ 140