Consolidated Statements of Cash Flows (FirstEnergy 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
Asset removal costs charged to income	203	55	18
Amortization of regulatory assets, net	307	474	736
Deferral of storm costs	(375)	(145)	(14)
Nuclear fuel and lease amortization	210	201	168
Deferred purchased power and other costs	(238)	(278)	(254)
Deferred income taxes and investment tax credits, net	647	798	450
Impairments of long-lived assets	0	413	388
Investments impairments	27	19	33
Deferred rents and lease market valuation liability	(104)	(49)	(54)
Pensions and OPEB mark-to-market adjustment	609	507	190
Retirement benefits	(127)	(151)	(86)
Gain on asset sales	(17)	(545)	(2)
Commodity derivative transactions, net	(95)	(27)	(81)
Pension trust contribution	(600)	(372)	0
Cash collateral, net	16	(79)	(26)
Interest rate swap transactions	0	0	129
Gain on sales of investment securities held in trusts, net	(71)	(59)	(55)
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
Accrued interest	(12)	(12)	7
Accrued compensation and retirement benefits	(55)	69	21
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)
Common stock dividend payments	(920)	(881)	(670)
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)
Cash investments	102	60	66
Cash received in Allegheny merger	0	590	0
Cost of removal	(229)	(114)	(35)
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
SUPPLEMENTAL CASH FLOW INFORMATION:
Non-cash transaction: merger with Allegheny, common stock issued	0	4,354	0
Cash paid (received) during the year-
Interest (net of amounts capitalized)	962	935	662
Income taxes	$ (6)	$ (358)	$ (42)