Consolidated Statement of Cash Flows (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
OPERATING ACTIVITIES
Net Income	$ 1,141	$ 1,062	$ 1,003
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	955	884	840
Deferred income taxes	584	491	659
Rate case amortization and accruals	42	49	13
Common equity component of allowance for funds used during construction	(4)	(11)	(15)
Net derivative (gains)/losses	(68)	22	(19)
Other non-cash items (net)	(16)	144	(18)
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers, less allowance for uncollectibles	(99)	50	(126)
Materials and supplies, including fuel oil and gas in storage	26	(8)	7
Other receivables and other current assets	27	51	207
Prepayments	(14)	196	(210)
Accounts payable	111	(195)	(22)
Pensions and retiree benefits obligations	957	779	633
Pensions and retiree benefits contributions	(870)	(628)	(555)
Superfund and environmental remediation costs (net)	7	(9)	(3)
Accrued taxes	(26)	98	38
Accrued interest	(7)	5	(1)
Deferred charges, noncurrent assets and other regulatory assets	(292)	(139)	(287)
Deferred credits and other regulatory liabilities	92	234	80
Other assets	(31)		(9)
Other liabilities	84	62	166
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,599	3,137	2,381
INVESTING ACTIVITIES
Utility construction expenditures	(1,917)	(1,887)	(1,986)
Cost of removal less salvage	(175)	(167)	(149)
Non-utility construction expenditures	(152)	(80)	(28)
Acquisition of solar energy projects	(337)
Proceeds from grants related to renewable energy investments	30	4
Net investment in Pilesgrove solar project and other	28	(20)
Purchase of additional ownership interest in Honeoye Storage Corporation			(12)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(2,523)	(2,150)	(2,175)
FINANCING ACTIVITIES
Net proceeds of short-term debt	539
Preferred stock redemption	(239)
Issuance of long-term debt	400		1,095
Retirement of long-term debt	(305)	(4)	(1,011)
Issuance of common shares			306
Issuance of common shares for stock plans, net of repurchases	(9)	31	133
Debt issuance costs	(4)		(11)
Common stock dividends	(709)	(693)	(629)
Preferred stock dividends	(3)	(11)	(11)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(330)	(677)	(128)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(254)	310	78
BALANCE AT BEGINNING OF PERIOD	648	338	260
Balance at End of Period	394	648	338
Interest	571	563	583
Income taxes	46	(236)	(25)
CECONY [Member]
OPERATING ACTIVITIES
Net Income	1,017	989	904
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	894	829	787
Deferred income taxes	365	462	622
Rate case amortization and accruals	42	49	13
Common equity component of allowance for funds used during construction	(2)	(8)	(13)
Other non-cash items (net)	14	96	(12)
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers, less allowance for uncollectibles	(131)	48	(121)
Materials and supplies, including fuel oil and gas in storage	23	(2)	4
Other receivables and other current assets	(40)	170	11
Prepayments	4	(3)
Accounts payable	102	(132)	(17)
Pensions and retiree benefits obligations	860	678	575
Pensions and retiree benefits contributions	(804)	(576)	(507)
Superfund and environmental remediation costs (net)	9	(9)	(8)
Accrued taxes	94	95	13
Accrued interest		3	(7)
Deferred charges, noncurrent assets and other regulatory assets	(262)	(32)	(294)
Deferred credits and other regulatory liabilities	100	224	70
Other liabilities	61	52	185
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,346	2,933	2,205
INVESTING ACTIVITIES
Utility construction expenditures	(1,788)	(1,785)	(1,853)
Cost of removal less salvage	(170)	(162)	(145)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(1,958)	(1,947)	(1,998)
FINANCING ACTIVITIES
Net proceeds of short-term debt	421
Preferred stock redemption	(239)
Issuance of long-term debt	400		925
Retirement of long-term debt	(300)		(850)
Debt issuance costs	(4)		(9)
Capital contribution by parent			355
Dividend to parent	(682)	(681)	(670)
Preferred stock dividends	(3)	(11)	(11)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(407)	(692)	(260)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(19)	294	(53)
BALANCE AT BEGINNING OF PERIOD	372	78	131
Balance at End of Period	353	372	78
Interest	513	504	528
Income taxes	$ 62	$ (198)	$ (18)