Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income	$ 1,525	$ 1,245	$ 1,193
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,341	1,216	1,130
Deferred income taxes	485	783	653
Rate case amortization and accruals	(124)	(210)	(52)
Common equity component of allowance for funds used during construction	(11)	(10)	(5)
Net derivative (gains)/losses	(4)	(6)	3
Pre-tax gain on sale of retail electric supply business and solar electric production projects	(1)	(104)	0
Other non-cash items, net	(49)	142	77
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	(6)	(69)	96
Materials and supplies, including fuel oil and gas in storage	5	13	22
Other receivables and other current assets	(44)	54	(27)
Taxes receivable	15	87	58
Prepayments	(19)	20	(14)
Accounts payable	95	29	(79)
Pensions and retiree benefits obligations, net	414	609	756
Pensions and retiree benefits contributions	(467)	(515)	(756)
Accrued taxes	44	2	(10)
Accrued interest	(7)	14	4
Superfund and environmental remediation costs, net	(14)	69	22
Distributions from equity investments	108	68	31
System benefit charge	101	244	38
Deferred charges, noncurrent assets and other regulatory assets	2,376	(97)	(111)
Deferred credits and other regulatory liabilities	(2,524)	(68)	182
Other current and noncurrent liabilities	128	(57)	66
NET CASH FLOWS FROM OPERATING ACTIVITIES	3,367	3,459	3,277
INVESTING ACTIVITIES
Utility construction expenditures	(3,028)	(2,835)	(2,562)
Cost of removal less salvage	(248)	(206)	(219)
Non-utility construction expenditures	(415)	(845)	(492)
Proceeds from sale of assets	34	252	0
Restricted cash	7	(17)	(13)
Proceeds from the transfer of assets to NY Transco	0	122	0
Other investing activities	37	31	(72)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,703)	(4,976)	(3,657)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	(477)	(475)	729
Issuance of long-term debt	1,697	2,590	1,147
Retirement of long-term debt	(434)	(735)	(500)
Debt issuance costs	(19)	(24)	(15)
Common stock dividends	(803)	(763)	(733)
Issuance of common shares - public offering	343	702	0
Issuance of common shares for stock plans, net of repurchases	51	51	1
Distribution to noncontrolling interest	(1)	(1)	0
NET CASH FLOWS FROM FINANCING ACTIVITIES	357	1,345	629
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	21	(172)	249
BALANCE AT BEGINNING OF PERIOD	776	944	699
BALANCE AT END OF PERIOD	797	772	948
LESS: CHANGE IN CASH BALANCES HELD FOR SALE	0	(4)	4
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	797	776	944
Cash paid/(received) during the period for:
Interest	725	664	597
Income taxes	(29)	(180)	(36)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	432	388	279
Issuance of common shares for dividend reinvestment	46	46	28
Debt assumed with business acquisitions	0	195	0
Electric and Gas Transmission Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(45)	(1,076)	0
Renewable Electric Production Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(45)	(402)	(299)
CECONY
OPERATING ACTIVITIES
Net income	1,104	1,056	1,084
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,195	1,106	1,040
Deferred income taxes	575	545	449
Rate case amortization and accruals	(142)	(227)	(74)
Common equity component of allowance for funds used during construction	(10)	(8)	(4)
Other non-cash items, net	(61)	(31)	(27)
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	15	(23)	87
Materials and supplies, including fuel oil and gas in storage	(17)	18	24
Other receivables and other current assets	8	(11)	38
Accounts receivables from affiliated companies	45	81	(58)
Prepayments	(8)	13	13
Accounts payable	125	20	(51)
Accounts payable to affiliated companies	0	(2)	(11)
Pensions and retiree benefits obligations, net	370	579	714
Pensions and retiree benefits contributions	(420)	(476)	(703)
Accrued taxes	52	1	3
Accrued taxes to affiliated companies	(47)	117	(8)
Accrued interest	2	(7)	1
Superfund and environmental remediation costs, net	(12)	79	19
System benefit charge	85	221	38
Deferred charges, noncurrent assets and other regulatory assets	2,212	(172)	(150)
Deferred credits and other regulatory liabilities	(2,242)	179	379
Other current and noncurrent liabilities	37	(20)	16
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,866	3,038	2,819
INVESTING ACTIVITIES
Utility construction expenditures	(2,840)	(2,672)	(2,410)
Cost of removal less salvage	(240)	(203)	(212)
Restricted cash	2	14	(16)
Proceeds from the transfer of assets to NY Transco	0	122	0
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,078)	(2,739)	(2,638)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	(450)	(433)	583
Issuance of long-term debt	1,200	1,300	650
Retirement of long-term debt	0	(650)	(350)
Debt issuance costs	(15)	(13)	(7)
Capital contribution by parent	301	100	13
Dividend to parent	(796)	(744)	(872)
NET CASH FLOWS FROM FINANCING ACTIVITIES	240	(440)	17
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	28	(141)	198
BALANCE AT BEGINNING OF PERIOD	702	843	645
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	730	702	843
Cash paid/(received) during the period for:
Interest	602	581	554
Income taxes	108	(162)	163
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	$ 351	$ 295	$ 210