Consolidated Statements of Cash Flows (FirstEnergy Corp.) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income (loss)	$ (6,177)	$ 578	$ 299
Adjustments to reconcile net income (loss) to net cash from operating activities-
Depreciation and amortization, including nuclear fuel, intangible assets and deferred debt-related costs	1,997	1,922	1,592
Impairment of assets	10,665	42	0
Investment impairment, including equity method investments	21	464	37
Pension and OPEB mark-to-market adjustment	147	242	835
Deferred income taxes and investment tax credits, net	(3,063)	284	162
Deferred costs on sale leaseback transaction, net	49	48	48
Deferred purchased power and fuel costs	(30)	(105)	(115)
Asset removal costs charged to income	54	55	28
Retirement benefits	64	(20)	(53)
Commodity derivative transactions, net (Note 11)	9	(73)	64
Pension trust contributions	(382)	(143)	0
Gain on sale of investment securities held in trusts	(50)	(23)	(64)
Lease payments on sale and leaseback transaction	(120)	(131)	(137)
Income from discontinued operations (Note 20)	0	0	(86)
Changes in current assets and liabilities-
Receivables	(11)	184	139
Materials and supplies	41	(15)	(65)
Prepayments and other current assets	27	(10)	126
Accounts payable	(37)	(243)	42
Accrued taxes	61	29	(165)
Accrued compensation and benefits	29	5	(22)
Other current liabilities	56	69	54
Cash collateral, net	(116)	140	(54)
Other	137	148	48
Net cash provided from operating activities	3,371	3,447	2,713
New Financing-
Long-term debt	1,976	1,311	4,528
Short-term borrowings, net	975	0	0
Redemptions and Repayments-
Long-term debt	(2,331)	(879)	(1,759)
Short-term borrowings, net	0	(91)	(1,605)
Common stock dividend payments	(611)	(607)	(604)
Other	(31)	(13)	(47)
Net cash (used for) provided from financing activities	(22)	(279)	513
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(2,835)	(2,704)	(3,312)
Nuclear fuel	(232)	(190)	(233)
Proceeds from asset sales	15	20	394
Sales of investment securities held in trusts	1,678	1,534	2,133
Purchases of investment securities held in trusts	(1,789)	(1,648)	(2,236)
Asset removal costs	(145)	(142)	(153)
Other	27	8	48
Net cash used for investing activities	(3,281)	(3,122)	(3,359)
Net change in cash and cash equivalents	68	46	(133)
Cash and cash equivalents at beginning of period	131	85	218
Cash and cash equivalents at end of period	199	131	85
SUPPLEMENTAL CASH FLOW INFORMATION:
Non-cash transaction: stock contribution to pension plan	500	0	0
Interest (net of amounts capitalized)	1,050	1,028	931
Income taxes (received), net of refunds	$ (16)	$ 37	$ (103)