Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net Income	$ 1,144	$ 1,440	$ 1,382
Net income	1,101	1,343	1,382
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,920	1,684	1,438
Impairment of assets	320	0	0
Deferred income taxes	85	308	408
Rate case amortization and accruals	(40)	(116)	(117)
Common equity component of allowance for funds used during construction	(17)	(14)	(12)
Net derivative (gains)/losses	57	27	8
(Gain) on Sale of Assets	0	(14)	0
Unbilled revenue and net unbilled revenue deferrals	(1)	(3)	18
(Gain) on existing project interests due to acquisition of Sempra Solar Holdings, LLC	0	0	(131)
Other non-cash items, net	127	(18)	115
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	(543)	23	(140)
Materials and supplies, including fuel oil and gas in storage	(4)	6	(20)
Revenue decoupling mechanism receivable	(61)	(76)	0
Other receivables and other current assets	(134)	54	(62)
Taxes receivable	(6)	29	27
Prepayments	(11)	(73)	(7)
Accounts payable	170	10	(46)
Pensions and retiree benefits obligations, net	285	357	325
Pensions and retiree benefits contributions	(478)	(357)	(479)
Accrued taxes	74	10	(49)
Accrued interest	(4)	24	(35)
Superfund and environmental remediation costs, net	(22)	(9)	(19)
Distributions from equity investments	39	57	107
System benefit charge	(119)	20	92
Deferred charges, noncurrent assets and other regulatory assets	(653)	(492)	(393)
Deferred credits and other regulatory liabilities	10	278	436
Other current and noncurrent liabilities	60	(21)	(151)
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,198	3,134	2,695
INVESTING ACTIVITIES
Utility construction expenditures	(3,326)	(3,238)	(3,251)
Cost of removal less salvage	(310)	(295)	(258)
Non-utility construction expenditures	(583)	(248)	(246)
Acquisition of Sempra Solar Holdings, LLC, net of cash acquired	0	0	(1,488)
Proceeds from sale of assets	0	192	5
Other investing activities	22	22	34
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(4,224)	(3,782)	(5,471)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	178	(874)	1,989
Issuance of long-term debt	2,925	3,017	3,030
Retirement of long-term debt	(518)	(1,195)	(1,938)
Debt issuance costs	(47)	(32)	(61)
Common stock dividends	(975)	(924)	(842)
Issuance of common shares - public offering	640	825	705
Issuance of common shares for stock plans	58	54	53
Distribution to noncontrolling interest	(16)	(12)	2
NET CASH FLOWS FROM FINANCING ACTIVITIES	2,245	859	2,938
CASH, TEMPORARY CASH INVESTMENTS AND RESTRICTED CASH:
NET CHANGE FOR THE PERIOD	219	211	162
BALANCE AT BEGINNING OF PERIOD	1,217	1,006	844
BALANCE AT END OF PERIOD	1,436	1,217	1,006
Cash paid/(received) during the period for:
Interest	920	876	805
Income taxes	38	(26)	0
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	478	336	369
Issuance of common shares for dividend reinvestment	48	47	47
Debt assumed with business acquisitions	0	0	568
Electric and Gas Transmission Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(3)	(205)	(248)
Renewable Electric Production Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(24)	(10)	(19)
CECONY
OPERATING ACTIVITIES
Net income	1,185	1,250	1,196
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,598	1,373	1,276
Deferred income taxes	168	128	354
Rate case amortization and accruals	(40)	(117)	(133)
Common equity component of allowance for funds used during construction	(14)	(12)	(11)
(Gain) on Sale of Assets	0	(14)	0
Unbilled revenue and net unbilled revenue deferrals	(47)	(3)	(4)
Other non-cash items, net	66	7	13
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	(516)	3	(153)
Materials and supplies, including fuel oil and gas in storage	2	11	(17)
Revenue decoupling mechanism receivable	(53)	(76)	0
Other receivables and other current assets	(49)	54	(96)
Accounts receivables from affiliated companies	(61)	141	(150)
Prepayments	19	(61)	(9)
Accounts payable	145	(7)	(27)
Accounts payable to affiliated companies	9	(4)	7
Pensions and retiree benefits obligations, net	253	330	293
Pensions and retiree benefits contributions	(438)	(325)	(440)
Accrued taxes	61	11	(47)
Accrued taxes to affiliated companies	1	0	(72)
Accrued interest	13	1	(1)
Superfund and environmental remediation costs, net	(30)	(12)	(18)
System benefit charge	(112)	18	86
Deferred charges, noncurrent assets and other regulatory assets	(603)	(486)	(314)
Deferred credits and other regulatory liabilities	92	306	549
Other current and noncurrent liabilities	44	(14)	(78)
NET CASH FLOWS FROM OPERATING ACTIVITIES	1,693	2,502	2,204
INVESTING ACTIVITIES
Utility construction expenditures	(3,112)	(3,028)	(3,051)
Cost of removal less salvage	(304)	(288)	(255)
Proceeds from sale of assets	0	192	0
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,416)	(3,124)	(3,306)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	523	(55)	1,042
Issuance of long-term debt	2,200	1,300	2,740
Retirement of long-term debt	(350)	(475)	(1,836)
Debt issuance costs	(34)	(21)	(30)
Capital contribution by parent	500	900	120
Dividend to parent	(982)	(912)	(846)
NET CASH FLOWS FROM FINANCING ACTIVITIES	1,857	737	1,190
CASH, TEMPORARY CASH INVESTMENTS AND RESTRICTED CASH:
NET CHANGE FOR THE PERIOD	134	115	88
BALANCE AT BEGINNING OF PERIOD	933	818	730
BALANCE AT END OF PERIOD	1,067	933	818
Cash paid/(received) during the period for:
Interest	693	676	662
Income taxes	102	73	195
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	417	285	299
Software Licenses
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Capital expenditures incurred but unpaid as of end of period	51	80	100
Software Licenses | CECONY
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Capital expenditures incurred but unpaid as of end of period	48	76	95
Equipment
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Capital expenditures incurred but unpaid as of end of period	28	33	0
Equipment | CECONY
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Capital expenditures incurred but unpaid as of end of period	$ 28	$ 33	$ 0