Consolidated Edison (ED) 10-K 21 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	ED
Entity Registrant Name	CONSOLIDATED EDISON INC
Entity Central Index Key	1,047,862
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		321,077,152
Entity Public Float			$ 24.3
CECONY
Document Information [Line Items]
Entity Registrant Name	CONSOLIDATED EDISON CO OF NEW YORK INC
Entity Central Index Key	23,632
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false

Consolidated Income Statement

Consolidated Income Statement - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING REVENUES
Total operating revenues	$ 12,337	$ 12,033	$ 12,075
OPERATING EXPENSES
Depreciation and amortization	1,438	1,341	1,216
Taxes, other than income taxes	2,266	2,155	2,031
TOTAL OPERATING EXPENSES	9,804	9,260	9,399
Gain on sale of solar electric production project in 2017 and retail electric supply business in 2016	0	1	104
Gain on acquisition of Sempra Solar Holdings, LLC	131	0	0
OPERATING INCOME	2,664	2,774	2,780
OTHER INCOME (DEDUCTIONS)
Investment income	119	111	75
Other income	17	15	16
Allowance for equity funds used during construction	12	11	10
Other deductions	(210)	(185)	(242)
TOTAL OTHER INCOME	(62)	(48)	(141)
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	2,602	2,726	2,639
INTEREST EXPENSE
Interest on long-term debt	780	726	678
Other interest	49	11	24
Allowance for borrowed funds used during construction	(10)	(8)	(6)
NET INTEREST EXPENSE	819	729	696
INCOME BEFORE INCOME TAX EXPENSE	1,783	1,997	1,943
INCOME TAX EXPENSE	401	472	698
NET INCOME	$ 1,382	$ 1,525	$ 1,245
Net income per common share — basic (in dollars per share)	$ 4.43	$ 4.97	$ 4.15
Net income per common share — diluted (in dollars per share)	$ 4.42	$ 4.94	$ 4.12
AVERAGE NUMBER OF SHARES OUTSTANDING — BASIC (in shares)	311.7	307.1	300.4
AVERAGE NUMBER OF SHARES OUTSTANDING — DILUTED (in shares)	312.9	308.8	301.9
CECONY
OPERATING REVENUES
Total operating revenues	$ 10,680	$ 10,468	$ 10,165
OPERATING EXPENSES
Depreciation and amortization	1,276	1,195	1,106
Taxes, other than income taxes	2,156	2,057	1,932
TOTAL OPERATING EXPENSES	8,326	7,919	7,714
OPERATING INCOME	2,354	2,549	2,451
OTHER INCOME (DEDUCTIONS)
Investment income	13	14	8
Allowance for equity funds used during construction	11	10	8
Other deductions	(167)	(161)	(205)
TOTAL OTHER INCOME	(143)	(137)	(189)
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	2,211	2,412	2,262
INTEREST EXPENSE
Interest on long-term debt	662	615	588
Other interest	36	14	19
Allowance for borrowed funds used during construction	(9)	(6)	(4)
NET INTEREST EXPENSE	689	623	603
INCOME BEFORE INCOME TAX EXPENSE	1,522	1,789	1,659
INCOME TAX EXPENSE	326	685	603
NET INCOME	1,196	1,104	1,056
Electric
OPERATING REVENUES
Total operating revenues	8,612	8,612	8,741
Electric | CECONY
OPERATING REVENUES
Total operating revenues	7,971	7,972	8,106
Gas
OPERATING REVENUES
Total operating revenues	2,327	2,133	1,692
OPERATING EXPENSES
Operating costs	1,041	808	477
Gas | CECONY
OPERATING REVENUES
Total operating revenues	2,078	1,901	1,508
OPERATING EXPENSES
Operating costs	643	510	319
Steam
OPERATING REVENUES
Total operating revenues	631	595	551
Steam | CECONY
OPERATING REVENUES
Total operating revenues	631	595	551
Non-utility
OPERATING REVENUES
Total operating revenues	767	693	1,091
Power
OPERATING EXPENSES
Operating costs	1,644	1,601	2,439
Power | CECONY
OPERATING EXPENSES
Operating costs	1,433	1,415	1,568
Fuel
OPERATING EXPENSES
Operating costs	263	216	172
Fuel | CECONY
OPERATING EXPENSES
Operating costs	263	216	172
Other operations and maintenance
OPERATING EXPENSES
Operating costs	3,152	3,139	3,064
Other operations and maintenance | CECONY
OPERATING EXPENSES
Operating costs	$ 2,555	$ 2,526	$ 2,617

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
NET INCOME	$ 1,382	$ 1,525	$ 1,245
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	10	1	7
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	10	1	7
COMPREHENSIVE INCOME	1,392	1,526	1,252
CECONY
NET INCOME	1,196	1,104	1,056
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	1	1	2
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2
COMPREHENSIVE INCOME	$ 1,197	$ 1,105	$ 1,058

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES
Net income	$ 1,382	$ 1,525	$ 1,245
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,438	1,341	1,216
Deferred income taxes	408	485	783
Rate case amortization and accruals	(117)	(124)	(210)
Common equity component of allowance for funds used during construction	(12)	(11)	(10)
Net derivative (gains)/losses	8	(4)	(6)
Unbilled revenue and net unbilled revenue deferrals	18	(113)	(71)
(Gain) on sale of retail electric supply business and solar electric production projects	0	(1)	(104)
(Gain) on acquisition of Sempra Solar Holdings, LLC	(131)	0	0
Other non-cash items, net	115	5	198
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	(140)	9	(69)
Materials and supplies, including fuel oil and gas in storage	(20)	5	13
Other receivables and other current assets	(62)	0	69
Taxes receivable	27	15	87
Prepayments	(7)	(19)	20
Accounts payable	(46)	95	29
Pensions and retiree benefits obligations, net	325	414	609
Pensions and retiree benefits contributions	(479)	(467)	(515)
Accrued taxes	(49)	44	2
Accrued interest	(35)	(7)	14
Superfund and environmental remediation costs, net	(19)	(14)	69
Distributions from equity investments	107	108	68
System benefit charge	92	101	244
Deferred charges, noncurrent assets and other regulatory assets	(393)	2,376	(97)
Deferred credits and other regulatory liabilities	436	(2,524)	(68)
Other current and noncurrent liabilities	(151)	128	(57)
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,695	3,367	3,459
INVESTING ACTIVITIES
Utility construction expenditures	(3,251)	(3,028)	(2,835)
Cost of removal less salvage	(258)	(248)	(206)
Non-utility construction expenditures	(246)	(415)	(845)
Acquisition of Sempra Solar Holdings, LLC, net of cash acquired	(1,488)	0	0
Proceeds from sale of assets	5	34	252
Proceeds from the transfer of assets to NY Transco	0	0	122
Other investing activities	34	37	31
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(5,471)	(3,710)	(4,950)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	1,989	(477)	(475)
Issuance of long-term debt	3,030	1,697	2,590
Retirement of long-term debt	(1,938)	(434)	(735)
Debt issuance costs	(61)	(19)	(24)
Common stock dividends	(842)	(803)	(763)
Issuance of common shares - public offering	705	343	702
Issuance of common shares for stock plans	53	51	51
Distribution to noncontrolling interest	2	(1)	(1)
NET CASH FLOWS FROM FINANCING ACTIVITIES	2,938	357	1,345
CASH, TEMPORARY CASH INVESTMENTS AND RESTRICTED CASH:
NET CHANGE FOR THE PERIOD	162	14	(146)
BALANCE AT BEGINNING OF PERIOD		826	972
BALANCE AT END OF PERIOD			826
LESS: CHANGE IN CASH BALANCES HELD FOR SALE			(4)
BALANCE AT BEGINNING OF PERIOD	844	830
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	1,006	844	830
Cash paid/(received) during the period for:
Interest	805	725	664
Income taxes	0	(29)	(180)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	369	432	388
Issuance of common shares for dividend reinvestment	47	46	46
Debt assumed with business acquisitions	568	0	195
Software licenses acquired but unpaid as of end of period	100	0	0
Electric and Gas Transmission Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(248)	(45)	(1,076)
Renewable Electric Production Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(19)	(45)	(393)
CECONY
OPERATING ACTIVITIES
Net income	1,196	1,104	1,056
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	1,276	1,195	1,106
Deferred income taxes	354	575	545
Rate case amortization and accruals	(133)	(142)	(227)
Common equity component of allowance for funds used during construction	(11)	(10)	(8)
Unbilled revenue and net unbilled revenue deferrals	(4)	(17)	(36)
Other non-cash items, net	13	(59)	5
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable - customers	(153)	15	(23)
Materials and supplies, including fuel oil and gas in storage	(17)	(17)	18
Other receivables and other current assets	(96)	23	(11)
Accounts receivables from affiliated companies	(150)	45	81
Prepayments	(9)	(8)	13
Accounts payable	(27)	125	20
Accounts payable to affiliated companies	7	0	(2)
Pensions and retiree benefits obligations, net	293	370	579
Pensions and retiree benefits contributions	(440)	(420)	(476)
Accrued taxes	(47)	52	1
Accrued taxes to affiliated companies	(72)	(47)	117
Accrued interest	(1)	2	(7)
Superfund and environmental remediation costs, net	(18)	(12)	79
System benefit charge	86	85	221
Deferred charges, noncurrent assets and other regulatory assets	(314)	2,212	(172)
Deferred credits and other regulatory liabilities	549	(2,242)	179
Other current and noncurrent liabilities	(78)	37	(20)
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,204	2,866	3,038
INVESTING ACTIVITIES
Utility construction expenditures	(3,051)	(2,840)	(2,672)
Cost of removal less salvage	(255)	(240)	(203)
Proceeds from the transfer of assets to NY Transco	0	0	122
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,306)	(3,080)	(2,753)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	1,042	(450)	(433)
Issuance of long-term debt	2,740	1,200	1,300
Retirement of long-term debt	(1,836)	0	(650)
Debt issuance costs	(30)	(15)	(13)
Capital contribution by parent	120	301	100
Dividend to parent	(846)	(796)	(744)
NET CASH FLOWS FROM FINANCING ACTIVITIES	1,190	240	(440)
CASH, TEMPORARY CASH INVESTMENTS AND RESTRICTED CASH:
NET CHANGE FOR THE PERIOD	88	26	(155)
BALANCE AT BEGINNING OF PERIOD	730	704	859
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	818	730	704
Cash paid/(received) during the period for:
Interest	662	602	581
Income taxes	195	108	(162)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	299	351	295
Software licenses acquired but unpaid as of end of period	$ 95	$ 0	$ 0

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and temporary cash investments	$ 895	$ 797
Accounts receivable - customers, less allowance for uncollectible accounts	1,267	1,103
Other receivables, less allowance for uncollectible accounts	285	160
Taxes receivable	49	76
Accrued unbilled revenue	514	598
Fuel oil, gas in storage, materials and supplies, at average cost	358	334
Prepayments	187	178
Regulatory assets	76	67
Restricted cash	111	47
Other current assets	122	177
TOTAL CURRENT ASSETS	3,864	3,537
INVESTMENTS	1,766	2,001
UTILITY PLANT, AT ORIGINAL COST
General	3,331	3,008
TOTAL	45,371	42,731
Less: Accumulated depreciation	9,769	9,063
Net	35,602	33,668
Construction work in progress	1,978	1,605
NET UTILITY PLANT	37,580	35,273
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	4,000	1,776
Construction work in progress	169	551
NET PLANT	41,749	37,600
OTHER NONCURRENT ASSETS
Goodwill	440	428
Intangible assets, less accumulated amortization of $29 and $15 in 2018 and 2017, respectively	1,654	131
Regulatory assets	4,294	4,266
Other deferred charges and noncurrent assets	153	148
TOTAL OTHER NONCURRENT ASSETS	6,541	4,973
TOTAL ASSETS	53,920	48,111
CURRENT LIABILITIES
Long-term debt due within one year	650	1,298
Term Loan	825	0
Notes payable	1,741	577
Accounts payable	1,187	1,286
Customer deposits	351	346
Accrued taxes	61	108
Accrued interest	129	143
Accrued wages	109	105
Fair value of derivative liabilities	50	17
Regulatory liabilities	114	101
System benefit charge	627	535
Other current liabilities	363	386
TOTAL CURRENT LIABILITIES	6,207	4,902
NONCURRENT LIABILITIES
Provision for injuries and damages	146	153
Pensions and retiree benefits	1,228	1,443
Superfund and other environmental costs	779	737
Asset retirement obligations	450	314
Fair value of derivative liabilities	16	38
Deferred income taxes and unamortized investment tax credits	5,820	5,495
Regulatory liabilities	4,641	4,577
Other deferred credits and noncurrent liabilities	299	296
TOTAL NONCURRENT LIABILITIES	13,379	13,053
LONG-TERM DEBT	17,495	14,731
EQUITY
Common shareholders’ equity	16,726	15,418
Noncontrolling interest	113	7
TOTAL EQUITY (See Statement of Equity)	16,839	15,425
TOTAL LIABILITIES AND EQUITY	53,920	48,111
Electric
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	30,378	28,994
Gas
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	9,100	8,256
Steam
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,562	2,473
CECONY
CURRENT ASSETS
Cash and temporary cash investments	818	730
Accounts receivable - customers, less allowance for uncollectible accounts	1,163	1,009
Other receivables, less allowance for uncollectible accounts	211	92
Taxes receivable	5	19
Accrued unbilled revenue	392	454
Accounts receivable from affiliated companies	214	64
Fuel oil, gas in storage, materials and supplies, at average cost	304	287
Prepayments	117	108
Regulatory assets	64	62
Other current assets	69	84
TOTAL CURRENT ASSETS	3,357	2,909
INVESTMENTS	385	383
UTILITY PLANT, AT ORIGINAL COST
General	3,056	2,753
TOTAL	42,508	40,024
Less: Accumulated depreciation	8,988	8,321
Net	33,520	31,703
Construction work in progress	1,850	1,502
NET UTILITY PLANT	35,370	33,205
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	4	4
NET PLANT	35,374	33,209
OTHER NONCURRENT ASSETS
Goodwill	245	245
Regulatory assets	3,923	3,863
Other deferred charges and noncurrent assets	69	87
TOTAL OTHER NONCURRENT ASSETS	3,992	3,950
TOTAL ASSETS	43,108	40,451
CURRENT LIABILITIES
Long-term debt due within one year	475	1,200
Notes payable	1,192	150
Accounts payable	977	1,057
Customer deposits	339	334
Accounts payable to affiliated companies	17	10
Accrued taxes	55	102
Accrued taxes to affiliated companies	0	72
Accrued interest	112	113
Accrued wages	99	95
Fair value of derivative liabilities	25	12
Regulatory liabilities	73	65
System benefit charge	569	483
Other current liabilities	267	245
TOTAL CURRENT LIABILITIES	4,200	3,938
NONCURRENT LIABILITIES
Provision for injuries and damages	141	147
Pensions and retiree benefits	952	1,140
Superfund and other environmental costs	693	637
Asset retirement obligations	292	287
Fair value of derivative liabilities	6	31
Deferred income taxes and unamortized investment tax credits	5,739	5,306
Regulatory liabilities	4,258	4,219
Other deferred credits and noncurrent liabilities	241	242
TOTAL NONCURRENT LIABILITIES	12,322	12,009
LONG-TERM DEBT	13,676	12,065
EQUITY
Common shareholders’ equity	12,910	12,439
TOTAL LIABILITIES AND EQUITY	43,108	40,451
CECONY | Electric
CURRENT ASSETS
Accrued unbilled revenue	6
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	28,595	27,299
CECONY | Gas
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	8,295	7,499
CECONY | Steam
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	$ 2,562	$ 2,473

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounts receivable - customers, allowance for uncollectible accounts	$ 62	$ 63
Other receivables, allowance for uncollectible accounts	5	8
Non-utility property, accumulated depreciation	275	201
Intangible assets, accumulated amortization	29	15
CECONY
Accounts receivable - customers, allowance for uncollectible accounts	57	58
Other receivables, allowance for uncollectible accounts	3	7
Non-utility property, accumulated depreciation	$ 25	$ 25

Consolidated Statement of Equit

Consolidated Statement of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Capital Stock Expense	Accumulated Other Comprehensive Income/(Loss)	Noncontrolling Interest	CECONY	CECONYCommon Stock	CECONYAdditional Paid-In Capital	CECONYRetained Earnings	CECONYRepurchased Con Edison Stock	CECONYCapital Stock Expense	CECONYAccumulated Other Comprehensive Income/(Loss)
BALANCE AS OF BEGINNING OF PERIOD (in shares) at Dec. 31, 2015		293,000,000								235,000,000
BALANCE AS OF BEGINNING OF PERIOD at Dec. 31, 2015	$ 13,061	$ 32	$ 5,030	$ 9,123	$ (1,038)	$ (61)	$ (34)	$ 9							$ (9)
BALANCE AS OF BEGINNING OF PERIOD at Dec. 31, 2015									$ 11,415	$ 589	$ 4,247	$ 7,611	$ (962)	$ (61)	(9)
TREASURY STOCK, BALANCE AS OF BEGINNING OF PERIOD (in shares) at Dec. 31, 2015					23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,245			1,245					1,056			1,056
Common stock dividends	(809)			(809)					(744)			(744)
Issuance of common shares - public offering (in shares)		10,000,000
Issuance of common shares - public offering	702	$ 1	723			(22)
Issuance of common shares for stock plans (in shares)		2,000,000
Issuance of common shares for stock plans	101		101
Capital contribution by parent									100		100
Other comprehensive income	7						7		2						2
Noncontrolling interest	(1)							(1)
BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2016		305,000,000								235,000,000
BALANCE AS OF END OF PERIOD at Dec. 31, 2016	14,306	$ 33	5,854	9,559	$ (1,038)	(83)	(27)	8							(7)
BALANCE AS OF END OF PERIOD at Dec. 31, 2016									11,829	$ 589	4,347	7,923	(962)	(61)	(7)
TREASURY STOCK, BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2016					23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,525			1,525					1,104			1,104
Common stock dividends	(849)			(849)					(796)			(796)
Issuance of common shares - public offering (in shares)		5,000,000
Issuance of common shares - public offering	343	$ 1	344			(2)
Issuance of common shares for stock plans	100		100
Capital contribution by parent									301		302			(1)
Other comprehensive income	1						1		1						1
Noncontrolling interest	(1)							(1)
BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2017		310,000,000								235,000,000
BALANCE AS OF END OF PERIOD at Dec. 31, 2017	15,425	$ 34	6,298	10,235	$ (1,038)	(85)	(26)	7							(6)
BALANCE AS OF END OF PERIOD at Dec. 31, 2017	15,418								12,439	$ 589	4,649	8,231	(962)	(62)	(6)
TREASURY STOCK, BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2017					23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,382			1,382					1,196			1,196
Common stock dividends	(889)			(889)					(846)			(846)
Issuance of common shares - public offering (in shares)		11,000,000
Issuance of common shares - public offering	705		719			(14)
Issuance of common shares for stock plans	100		100
Capital contribution by parent									120		120
Other comprehensive income	10						10		$ 1						1
Noncontrolling interest	106							106
BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2018		321,000,000							21,976,200	235,000,000
BALANCE AS OF END OF PERIOD at Dec. 31, 2018	16,839	$ 34	$ 7,117	$ 10,728	$ (1,038)	$ (99)	$ (16)	$ 113							(5)
BALANCE AS OF END OF PERIOD at Dec. 31, 2018	$ 16,726								$ 12,910	$ 589	$ 4,769	$ 8,581	$ (962)	$ (62)	$ (5)
TREASURY STOCK, BALANCE AS OF END OF PERIOD (in shares) at Dec. 31, 2018					23,000,000

Consolidated Statement of Equ_2

Consolidated Statement of Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Common stock dividends per share (in dollars per share)	$ 2.86	$ 2.76	$ 2.68

Consolidated Statement of Capit

Consolidated Statement of Capitalization - USD ($) shares in Millions, $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	321	310
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 16,742	$ 15,444
Pension plan liability adjustments, net of taxes	(12)	(23)
Unrealized losses on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment for unrealized losses included in regulatory assets, net of taxes	(4)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(16)	(26)
Equity	16,726	15,418
Noncontrolling interest	113	7
TOTAL EQUITY (See Statement of Equity)	$ 16,839	$ 15,425
CECONY
Schedule of Capitalization, Equity [Line Items]
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS (in shares)	235	235
TOTAL EQUITY BEFORE ACCUMULATED OTHER COMPREHENSIVE LOSS	$ 12,915	$ 12,445
Pension plan liability adjustments, net of taxes	0	(3)
Unrealized losses on derivatives qualified as cash flow hedges, less reclassification adjustment for gains/(losses) included in net income and reclassification adjustment for unrealized losses included in regulatory assets, net of taxes	(5)	(3)
TOTAL ACCUMULATED OTHER COMPREHENSIVE LOSS, NET OF TAXES	(5)	(6)
Equity	12,910	12,439
TOTAL SHAREHOLDER’S EQUITY (See Statement of Shareholder’s Equity)	$ 12,910	$ 12,439

Consolidated Statement of Cap_2

Consolidated Statement of Capitalization - Long-term Debt - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Schedule of Capitalization, Long-term Debt [Line Items]
Other long-term debt		$ 304	$ 310
Unamortized debt expense		(152)	(113)
Unamortized debt discount		(33)	(29)
TOTAL		18,145	16,029
Less: Long-term debt due within one year		650	1,298
TOTAL LONG-TERM DEBT		17,495	14,731
TOTAL CAPITALIZATION		34,221	30,149
CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Unamortized debt expense		(107)	(94)
Unamortized debt discount		(32)	(27)
TOTAL		14,151	13,265
Less: Long-term debt due within one year		475	1,200
TOTAL LONG-TERM DEBT		13,676	12,065
TOTAL CAPITALIZATION		26,586	24,504
Copper Mountain Solar 2
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		230	0
Coram
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 160	170
Coram | Maximum
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.52%
Copper Mountain Solar 3
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 298	0
Wind Holdings
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.41%
TOTAL PROJECT DEBT		$ 137	0
Copper Mountain Solar 1
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		70	0
Mesquite Solar 1
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 208	0
Mesquite Solar 1 | Minimum
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.24%
Mesquite Solar 1 | Maximum
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.03%
Broken Bow II
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.82%
TOTAL PROJECT DEBT		$ 69	0
Texas Solar 4
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		$ 58	61
Texas Solar 4 | Minimum
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.95%
Texas Solar 4 | Maximum
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.25%
California Solar 2
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.94%
TOTAL PROJECT DEBT		$ 103	110
California Solar 3
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.07%
TOTAL PROJECT DEBT		$ 89	93
California Solar
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.78%
TOTAL PROJECT DEBT		$ 190	0
Texas Solar 5
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.53%
TOTAL PROJECT DEBT		$ 150	155
Texas Solar 7
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.21%
TOTAL PROJECT DEBT		$ 206	214
Upton County Solar
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL PROJECT DEBT		$ 94	97
Other project debt
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		14	15
Project Debt
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT		2,076	915
Debentures
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		15,500	13,860
Debentures | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		$ 13,840	12,300
Debentures | Debenture Series 2008A, 5.85% Due 2018
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.85%
TOTAL		$ 0	600
Debentures | Debenture Series 2008A, 5.85% Due 2018 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.85%
TOTAL		$ 0	600
Debentures | Debenture Series 2008A, 6.15% Due 2018
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.15%
TOTAL		$ 0	50
Debentures | Debenture Series 2008C, 7.125% Due 2018
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		7.125%
TOTAL		$ 0	600
Debentures | Debenture Series 2008C, 7.125% Due 2018 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		7.125%
TOTAL		$ 0	600
Debentures | Debenture Series 2009A, 4.96% Due 2019
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.96%
TOTAL		$ 60	60
Debentures | Debenture Series 2009B, 6.65% Due 2019
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.65%
TOTAL		$ 475	475
Debentures | Debenture Series 2009B, 6.65% Due 2019 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.65%
TOTAL		$ 475	475
Debentures | Debenture Series 2010A, 4.45% Due 2020
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL		$ 350	350
Debentures | Debenture Series 2010A, 4.45% Due 2020 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL		$ 350	350
Debentures | Debenture Series 2017A, 2.00% Due 2020
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.00%
TOTAL		$ 400	400
Debentures | Debenture Series 2018C, Variable Rate, Due 2021
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		640	0
Debentures | Debenture Series 2018C, Variable Rate, Due 2021 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		$ 640	0
Debentures | Debenture Series 2016A, 2.00% Due 2021
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.00%
TOTAL		$ 500	500
Debentures | Debenture Series 2014B, 3.30% Due 2024
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.30%
TOTAL		$ 250	250
Debentures | Debenture Series 2014B, 3.30% Due 2024 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.30%
TOTAL		$ 250	250
Debentures | Debenture Series 2016B, 2.90% Due 2026
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.90%
TOTAL		$ 250	250
Debentures | Debenture Series 2016B, 2.90% Due 2026 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		2.90%
TOTAL		$ 250	250
Debentures | Debenture Series 1997F, 6.50% Due 2027
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.50%
TOTAL		$ 80	80
Debentures | Debenture Series 2017B, 3.125% Due 2027
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.125%
TOTAL		$ 350	350
Debentures | Debenture Series 2017B, 3.125% Due 2027 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.125%
TOTAL		$ 350	350
Debentures | Debenture Series 2018A, 3.80% Due 2028
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.80%
TOTAL		$ 300	0
Debentures | Debenture Series 2018A, 3.80% Due 2028 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.80%
TOTAL		$ 300	0
Debentures | Debenture Series 2018D, 4.00% Due 2028
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.00%
TOTAL		$ 500	0
Debentures | Debenture Series 2018D, 4.00% Due 2028 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.00%
TOTAL		$ 500	0
Debentures | Debenture Series 2003A, 5.875% Due 2033
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.875%
TOTAL		$ 175	175
Debentures | Debenture Series 2003A, 5.875% Due 2033 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.875%
TOTAL		$ 175	175
Debentures | Debenture Series 2003C, 5.10% Due 2033
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.10%
TOTAL		$ 200	200
Debentures | Debenture Series 2003C, 5.10% Due 2033 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.10%
TOTAL		$ 200	200
Debentures | Debenture Series 2004B, 5.70% Due 2034
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 200	200
Debentures | Debenture Series 2004B, 5.70% Due 2034 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 200	200
Debentures | Debenture Series 2005A, 5.30% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.30%
TOTAL		$ 350	350
Debentures | Debenture Series 2005A, 5.30% Due 2035 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.30%
TOTAL		$ 350	350
Debentures | Debenture Series 2005B, 5.25% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.25%
TOTAL		$ 125	125
Debentures | Debenture Series 2005B, 5.25% Due 2035 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.25%
TOTAL		$ 125	125
Debentures | Debenture Series 2006A, 5.85% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.85%
TOTAL		$ 400	400
Debentures | Debenture Series 2006A, 5.85% Due 2036 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.85%
TOTAL		$ 400	400
Debentures | Debenture Series 2006B, 6.20% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.20%
TOTAL		$ 400	400
Debentures | Debenture Series 2006B, 6.20% Due 2036 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.20%
TOTAL		$ 400	400
Debentures | Debenture Series 2006E, 5.70% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 250	250
Debentures | Debenture Series 2006E, 5.70% Due 2036 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 250	250
Debentures | Debenture Series 2007A, 6.30% Due 2037
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.30%
TOTAL		$ 525	525
Debentures | Debenture Series 2007A, 6.30% Due 2037 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.30%
TOTAL		$ 525	525
Debentures | Debenture Series 2008B, 6.75% Due 2038
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.75%
TOTAL		$ 600	600
Debentures | Debenture Series 2008B, 6.75% Due 2038 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.75%
TOTAL		$ 600	600
Debentures | Debenture Series 2009B, 6.00% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		6.00%
TOTAL		$ 60	60
Debentures | Debenture Series 2009C, 5.50% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL		$ 600	600
Debentures | Debenture Series 2009C, 5.50% Due 2039 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL		$ 600	600
Debentures | Debenture Series 2010B, 5.70% Due 2040
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 350	350
Debentures | Debenture Series 2010B, 5.70% Due 2040 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.70%
TOTAL		$ 350	350
Debentures | Debenture Series 2010B, 5.50% Due 2040
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		5.50%
TOTAL		$ 115	115
Debentures | Debenture Series 2012A, 4.20% Due 2042
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.20%
TOTAL		$ 400	400
Debentures | Debenture Series 2012A, 4.20% Due 2042 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.20%
TOTAL		$ 400	400
Debentures | Debenture Series 2013A, 3.95% Due 2043
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.95%
TOTAL		$ 700	700
Debentures | Debenture Series 2013A, 3.95% Due 2043 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.95%
TOTAL		$ 700	700
Debentures | Debenture Series 2014A, 4.45% Due 2044
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL		$ 850	850
Debentures | Debenture Series 2014A, 4.45% Due 2044 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.45%
TOTAL		$ 850	850
Debentures | Debenture Series 2015A, 4.50% due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL		$ 650	650
Debentures | Debenture Series 2015A, 4.50% due 2045 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL		$ 650	650
Debentures | Debenture Series 2015A, 4.95% due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.95%
TOTAL		$ 120	120
Debentures | Debenture Series 2015B, 4.69% due 2045
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.69%
TOTAL		$ 100	100
Debentures | Debenture Series 2016A, 3.85% Due 2046
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.85%
TOTAL		$ 550	550
Debentures | Debenture Series 2016A, 3.85% Due 2046 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.85%
TOTAL		$ 550	550
Debentures | Debenture Series 2016A. 3.88% Due 2046
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.88%
TOTAL		$ 75	75
Debentures | Debenture Series 2017A, 3.875% Due 2047
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.875%
TOTAL		$ 500	500
Debentures | Debenture Series 2017A, 3.875% Due 2047 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		3.875%
TOTAL		$ 500	500
Debentures | Debenture Series 2018E, 4.65% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.65%
TOTAL		$ 600	0
Debentures | Debenture Series 2018E, 4.65% Due 2048 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.65%
TOTAL		$ 600	0
Debentures | Debenture Series 2018A, 4.35% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.35%
TOTAL		$ 125	0
Debentures | Debenture Series 2018B, 4.35% Due 2048
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.35%
TOTAL		$ 25	0
Debentures | Debenture Series 2014C, 4.625% Due 2054
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.625%
TOTAL		$ 750	750
Debentures | Debenture Series 2014C, 4.625% Due 2054 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.625%
TOTAL		$ 750	750
Debentures | Debenture Series 2016C, 4.30% Due 2056
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.30%
TOTAL		$ 500	500
Debentures | Debenture Series 2016C, 4.30% Due 2056 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.30%
TOTAL		$ 500	500
Debentures | Debenture Series 2017C, 4.00% Due 2057
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.00%
TOTAL		$ 350	350
Debentures | Debenture Series 2017C, 4.00% Due 2057 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		400.00%
TOTAL		$ 350	350
Debentures | Debenture Series 2018B, 4.50% Due 2058
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL		$ 700	0
Debentures | Debenture Series 2018B, 4.50% Due 2058 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		4.50%
TOTAL		$ 700	0
Tax-Exempt Debt
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	450	1,086
Tax-Exempt Debt | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		450	1,086
Tax-Exempt Debt | Tax Exempt Debt Series 2004B Series 1, 2.45% Due 2032
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	0	127
Tax-Exempt Debt | Tax Exempt Debt Series 2004B Series 1, 2.45% Due 2032 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		0	127
Tax-Exempt Debt | Tax Exempt Debt Series 1999A, 1.834% Due 2034
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	0	293
Tax-Exempt Debt | Tax Exempt Debt Series 1999A, 1.834% Due 2034 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		0	293
Tax-Exempt Debt | Tax Exempt Debt Series 2004B Series 2, 1.68% Due 2035
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	0	20
Tax-Exempt Debt | Tax Exempt Debt Series 2004B Series 2, 1.68% Due 2035 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		0	20
Tax-Exempt Debt | Tax Exempt Debt Series 2001B, 1.796% Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	0	98
Tax-Exempt Debt | Tax Exempt Debt Series 2001B, 1.796% Due 2036 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		$ 0	98
Tax-Exempt Debt | Tax Exempt Debt Series 2010A Due 2036
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[1]	1.74%
TOTAL PROJECT DEBT	[1]	$ 225	225
Tax-Exempt Debt | Tax Exempt Debt Series 2010A Due 2036 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		1.74%
TOTAL		$ 225	225
Tax-Exempt Debt | Tax Exempt Debt Series 2004A, 1.943% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL PROJECT DEBT	[1]	0	98
Tax-Exempt Debt | Tax Exempt Debt Series 2004A, 1.943% Due 2039 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
TOTAL		$ 0	98
Tax-Exempt Debt | Tax Exempt Debt Series 2004C, 1.663% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[1]	1.75%
TOTAL PROJECT DEBT	[1]	$ 99	99
Tax-Exempt Debt | Tax Exempt Debt Series 2004C, 1.663% Due 2039 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		1.75%
TOTAL		$ 99	99
Tax-Exempt Debt | Tax-Exempt Debt Series 2005A, 1.627% Due 2039
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate	[1]	1.71%
TOTAL PROJECT DEBT	[1]	$ 126	126
Tax-Exempt Debt | Tax-Exempt Debt Series 2005A, 1.627% Due 2039 | CECONY
Schedule of Capitalization, Long-term Debt [Line Items]
Interest Rate		1.71%
TOTAL		$ 126	$ 126
[1]	Rates are to be reset weekly; December 31, 2018 rates shown.

General

General	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General These combined notes accompany and form an integral part of the separate consolidated financial statements of each of the two separate registrants: Consolidated Edison, Inc. and its subsidiaries (Con Edison) and Consolidated Edison Company of New York, Inc. and its subsidiaries (CECONY). CECONY is a subsidiary of Con Edison and as such its financial condition and results of operations and cash flows, which are presented separately in the CECONY consolidated financial statements, are also consolidated, along with those of Orange and Rockland Utilities, Inc. (O&R), Con Edison Clean Energy Businesses, Inc. (together with its subsidiaries, the Clean Energy Businesses) and Con Edison Transmission, Inc. (together with its subsidiaries, Con Edison Transmission) in Con Edison’s consolidated financial statements. The term “Utilities” is used in these notes to refer to CECONY and O&R. As used in these notes, the term “Companies” refers to Con Edison and CECONY and, except as otherwise noted, the information in these combined notes relates to each of the Companies. However, CECONY makes no representation as to information relating to Con Edison or the subsidiaries of Con Edison other than itself. Con Edison has two regulated utility subsidiaries: CECONY and O&R. CECONY provides electric service and gas service in New York City and Westchester County. The company also provides steam service in parts of Manhattan. O&R, along with its regulated utility subsidiary, provides electric service in southeastern New York and northern New Jersey and gas service in southeastern New York. Con Edison Clean Energy Businesses, Inc. has three subsidiaries: Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company that provides energy-related products and services to retail customers. In December 2018, a Con Edison Development subsidiary acquired Sempra Solar Holdings, LLC. Con Edison Transmission, Inc. invests in electric transmission facilities through its subsidiary, Consolidated Edison Transmission, LLC (CET Electric), and invests in gas pipeline and storage facilities through its subsidiary Con Edison Gas Pipeline and Storage, LLC (CET Gas). See Note U.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Other Matters	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Other Matters	Summary of Significant Accounting Policies and Other Matters Principles of Consolidation The Companies’ consolidated financial statements include the accounts of their respective majority-owned subsidiaries, and variable interest entities (see Note Q), as required. All intercompany balances and intercompany transactions have been eliminated. Accounting Policies The accounting policies of Con Edison and its subsidiaries conform to generally accepted accounting principles in the United States of America (GAAP). For the Utilities, these accounting principles include the accounting rules for regulated operations and the accounting requirements of the Federal Energy Regulatory Commission (FERC) and the state regulators having jurisdiction. The accounting rules for regulated operations specify the economic effects that result from the causal relationship of costs and revenues in the rate-regulated environment and how these effects are to be accounted for by a regulated enterprise. Revenues intended to cover some costs may be recorded either before or after the costs are incurred. If regulation provides assurance that incurred costs will be recovered in the future, these costs would be recorded as deferred charges or “regulatory assets” under the accounting rules for regulated operations. If revenues are recorded for costs that are expected to be incurred in the future, these revenues would be recorded as deferred credits or “regulatory liabilities” under the accounting rules for regulated operations. The Utilities’ principal regulatory assets and liabilities are detailed in Note B. The Utilities are receiving or being credited with a return on all of their regulatory assets for which a cash outflow has been made, and are paying or being charged with a return on all of their regulatory liabilities for which a cash inflow has been received. The Utilities’ regulatory assets and liabilities will be recovered from customers, or applied for customer benefit, in accordance with rate provisions approved by the applicable state regulators. Other significant accounting policies of the Companies are referenced below in this Note A and in the notes that follow. Revenues Adoption of New Standard On January 1, 2018, the Companies adopted Accounting Standards Codification (ASC) Topic 606, “Revenue from Contracts with Customers,” using the modified retrospective method applied to those contracts that were not completed. No charge to retained earnings for cumulative impact was required as a result of the Companies’ adoption of Topic 606. Revenue Recognition The following table presents, for the year ended December 31, 2018 , revenue from contracts with customers as defined in Topic 606, as well as additional revenue from sources other than contracts with customers, disaggregated by major source. (Millions of Dollars) Revenues from contracts with customers Other revenues (a) Total operating revenues CECONY Electric $7,920 $51 $7,971 Gas 2,052 26 2,078 Steam 625 6 631 Total CECONY $10,597 $83 $10,680 O&R Electric 647 (5) 642 Gas 256 (7) 249 Total O&R $903 $(12) $891 Clean Energy Businesses Renewables 329 (b) — 329 Energy services 95 — 95 Other — 339 339 Total Clean Energy Businesses $424 $339 $763 Con Edison Transmission 4 — 4 Other (c) — (1 ) (1 ) Total Con Edison $11,928 $409 $12,337 (a) For the Utilities, this includes revenue from alternative revenue programs, such as the revenue decoupling mechanisms under their New York electric and gas rate plans. For the Clean Energy Businesses, this includes revenue from wholesale services. (b) Included within the total for Renewables revenue at the Clean Energy Businesses is $103 million of revenue related to engineering, procurement and construction services. (c) Parent company and consolidation adjustments. Revenues are recorded as energy is delivered, generated or services are provided and billed to customers, except for services under percentage-of-completion contracts. Amounts billed are recorded in accounts receivable - customers, with payment generally due the following month. Con Edison’s and the Utilities’ accounts receivable - customers balance also reflects the Utilities’ purchase of receivables from energy service companies to support retail choice programs. Accrued revenues not yet billed to customers are recorded as accrued unbilled revenues. The Utilities have the obligation to deliver electricity, gas and steam energy to their customers. As the energy is immediately available for use upon delivery to the customer, the energy and its delivery are identifiable as a single performance obligation. The Utilities recognize revenues as this performance obligation is satisfied over time as the Utilities deliver, and the customers simultaneously receive and consume, the energy. The amount of revenues recognized reflects the consideration the Utilities expect to receive in exchange for delivering the energy. Under their tariffs, the transaction price for full-service customers includes the Utilities’ energy cost and for all customers includes delivery charges determined based on customer class and in accordance with established tariffs and guidelines of the New York State Public Service Commission (NYSPSC) or the New Jersey Board of Public Utilities (NJBPU), as applicable. Accordingly, there is no unsatisfied performance obligation associated with these customers. The transaction price is applied to the Utilities’ revenue generating activities through the customer billing process. Because energy is delivered over time, the Utilities use output methods that recognize revenue based on direct measurement of the value transferred, such as units delivered, which provides an accurate measure of value for the energy delivered. The Utilities accrue revenues at the end of each month for estimated energy delivered but not yet billed to customers. The Utilities defer over a 12 -month period net interruptible gas revenues, other than those authorized by the NYSPSC to be retained by the Utilities, for refund to firm gas sales and transportation customers. Con Edison Development recognizes revenue for the sale of energy from renewable electric production projects as energy is generated and billed to counterparties. Con Edison Development accrues revenues at the end of each month for energy generated but not yet billed to counterparties. Con Edison Energy recognizes revenue as energy is delivered and services are provided for managing energy supply assets leased from others and managing the dispatch, fuel requirements and risk management activities for generating plants and merchant transmission in the northeastern United States. Con Edison Solutions recognizes revenue for providing energy-efficiency services to government and commercial customers, and Con Edison Development recognizes revenue for engineering, procurement and construction services, under the percentage-of-completion method of revenue recognition. Sales and profits on each percentage-of-completion contract are recorded each month based on the ratio of actual cumulative costs incurred to the total estimated costs at completion of the contract, multiplied by the total estimated contract revenue, less cumulative revenues recognized in prior periods (the ‘‘cost-to-cost’’ method). The impact of revisions of contract estimates, which may result from contract modifications, performance or other reasons, are recognized on a cumulative catch-up basis in the period in which the revisions are made. (Millions of Dollars) Unbilled contract revenue (a) Unearned revenue (b) Beginning balance as of January 1, 2018 $58 $87 Additions (c) 144 38 Subtractions (c) 173 105 (d) Ending balance as of December 31, 2018 $29 $20 (a) Unbilled contract revenue represents accumulated incurred costs and earned profits on contracts (revenue arrangements), which have been recorded as revenue, but have not yet been billed to customers, and which represent contract assets as defined in Topic 606. Substantially all accrued unbilled contract revenue is expected to be collected within one year. Unbilled contract revenue arises from the cost-to-cost method of revenue recognition. Unbilled contract revenue from fixed-price type contracts is converted to billed receivables when amounts are invoiced to customers according to contractual billing terms, which generally occur when deliveries or other performance milestones are completed. (b) Unearned revenue represents a liability for billings to customers in excess of earned revenue, which are contract liabilities as defined in Topic 606. (c) Additions for unbilled contract revenue and subtractions for unearned revenue represent additional revenue earned. Additions for unearned revenue and subtractions for unbilled contract revenue represent billings. Activity also includes appropriate balance sheet classification for the period. (d) Of the $105 million in subtractions from unearned revenue, $50 million was included in the balance as of December 31, 2017. As of December 31, 2018 , the aggregate amount of the remaining fixed performance obligations is $95 million , of which $59 million will be recognized within the next two years, and the remaining $36 million will be recognized pursuant to long-term service and maintenance agreements. CECONY’s electric and gas rate plans and O&R’s New York electric and gas rate plans each contain a revenue decoupling mechanism under which the company’s actual energy delivery revenues are compared with the authorized delivery revenues and the difference accrued, with interest, for refund to, or recovery from, customers, as applicable. See “Rate Plans” in Note B. The NYSPSC requires utilities to record gross receipts tax revenues and expenses on a gross income statement presentation basis (i.e., included in both revenue and expense). The recovery of these taxes is generally provided for in the revenue requirement within each of the respective NYSPSC approved rate plans. Total excise taxes (inclusive of gross receipts taxes) recorded in operating revenues were as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $330 $302 $336 CECONY 318 292 316 Other Receivables Other Receivables includes costs related to aid provided by the Utilities in the restoration of power in Puerto Rico in the aftermath of September 2017 hurricanes. Such costs have fully been billed to the appropriate authorities. As of December 31, 2018 , Con Edison and CECONY other receivables' balances related to such costs were $104 million and $98 million , respectively. Plant and Depreciation Utility Plant Utility plant is stated at original cost. The cost of repairs and maintenance is charged to expense and the cost of betterments is capitalized. The capitalized cost of additions to utility plant includes indirect costs such as engineering, supervision, payroll taxes, pensions, other benefits and an allowance for funds used during construction (AFUDC). The original cost of property is charged to expense over the estimated useful lives of the assets. Upon retirement, the original cost of property is charged to accumulated depreciation. See Note R. Rates used for AFUDC include the cost of borrowed funds and a reasonable rate of return on the Utilities’ own funds when so used, determined in accordance with regulations of the FERC or the state public utility regulatory authority having jurisdiction. The rate is compounded semiannually, and the amounts applicable to borrowed funds are treated as a reduction of interest charges, while the amounts applicable to the Utilities’ own funds are credited to other income (deductions). The AFUDC rates for CECONY were 5.4 percent , 5.5 percent and 4.7 percent for 2018 , 2017 and 2016 , respectively. The AFUDC rates for O&R were 2.2 percent , 2.5 percent and 3.5 percent for 2018 , 2017 and 2016 , respectively. The Utilities generally compute annual charges for depreciation using the straight-line method for financial statement purposes, with rates based on average service lives and net salvage factors. The average depreciation rates for CECONY were 3.1 percent for 2018 , 2017 and 2016 . The average depreciation rates for O&R were 2.9 percent for 2018 , 2017 and 2016 . The estimated lives for utility plant for CECONY range from 5 to 95 years for electric, 5 to 100 years for gas, 5 to 80 years for steam and 5 to 55 years for general plant. For O&R, the estimated lives for utility plant range from 5 to 75 years for electric and gas and 5 to 50 years for general plant. At December 31, 2018 and 2017 , the capitalized cost of the Companies’ utility plant, net of accumulated depreciation, was as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Electric Generation $593 $544 $592 $544 Transmission 3,333 3,210 3,106 2,990 Distribution 19,750 18,959 18,716 17,996 Gas (a) 7,714 6,976 7,107 6,403 Steam 1,830 1,798 1,830 1,798 General 2,306 2,105 2,102 1,905 Held for future use 76 76 67 67 Construction work in progress 1,978 1,605 1,850 1,502 Net Utility Plant $37,580 $35,273 $35,370 $33,205 (a) Primarily distribution. At December 31, 2018 , general utility plant of Con Edison and CECONY included $100 million and $95 million , respectively, related to a May 2018 acquisition of software licenses. The software licenses asset is being amortized over a period of 15 years , and the estimated aggregate annual amortization expense for Con Edison and CECONY is $7 million . At December 31, 2018 , the accumulated amortization for Con Edison and CECONY was $3 million . Under the Utilities’ rate plans, the aggregate annual depreciation allowance for the period ended December 31, 2018 was $1,323 million , including $1,253 million under CECONY’s electric, gas and steam rate plans that have been approved by the NYSPSC. Non–Utility Plant Non-utility plant is stated at original cost. For Con Edison, non-utility plant consists primarily of the Clean Energy Businesses’ renewable electric production and gas storage. For the Utilities, non-utility plant consists of land and conduit for telecommunication use. Depreciation on these assets is computed using the straight-line method for financial statement purposes over their estimated useful lives, which range from 3 to 30 years . Goodwill Con Edison tests goodwill for impairment at least annually or whenever there is a triggering event. There is an option to first make a qualitative assessment of whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount before applying a two-step, quantitative goodwill impairment test. Con Edison has elected to perform the qualitative assessment for substantially all of its goodwill and, if needed, applies the two-step quantitative approach. The first step of the quantitative goodwill impairment test compares the estimated fair value of a reporting unit with its carrying value, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying value, goodwill of the reporting unit is considered not impaired. If the carrying value exceeds the estimated fair value of the reporting unit, the second step is performed to measure the amount of impairment loss, if any. The second step requires a calculation of the implied fair value of goodwill. In 2018, Con Edison recorded no impairment charge on goodwill. See Note K. Long–Lived and Intangible Assets Con Edison evaluates the impairment of long-lived assets and intangible assets with definite lives, based on projections of undiscounted future cash flows, which projections may vary significantly from future projections or actual cash flows, whenever events or changes in circumstances indicate that the carrying amounts of such assets may not be recoverable. In the event an evaluation indicates that such cash flows cannot be expected to be sufficient to fully recover the assets, the assets are written down to their estimated fair value. Con Edison's intangible assets with definite lives consist primarily of power purchase agreements, which were identified as part of purchase price allocations associated with acquisitions made by Con Edison Development in 2016 and 2018. At December 31, 2018 and 2017 , intangible assets arising from power purchase agreements, including the PG&E PPAs (discussed below), were $1,712 million and $131 million , net of accumulated amortization of $22 million and $9 million , respectively, and are being amortized over the life of each agreement. Excluding power purchase agreements, Con Edison’s other intangible assets were $3 million and an immaterial amount, net of accumulated amortization of $7 million and $6 million , at December 31, 2018 and 2017 , respectively. CECONY’s other intangible assets were immaterial at December 31, 2018 and 2017 . Con Edison recorded amortization expense related to its intangible assets of $ 14 million in 2018 , $9 million in 2017 and $2 million in 2016 . Con Edison expects amortization expense to be $105 million per year over the next five years. Con Edison recorded $2 million of impairment charges in 2018. No impairment charges were recorded on Con Edison's long-lived assets or intangible assets with definite lives in 2017 or 2016. In January 2019, Pacific Gas and Electric Company (PG&E) filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code. The output of Con Edison Development renewable electric production projects with an aggregate of 680 MW (AC) of generating capacity (PG&E Projects) is sold to PG&E under long-term power purchase agreements (PG&E PPAs). Most of the PG&E PPAs have contract prices that are higher than estimated market prices. PG&E, as a debtor in possession, may assume or reject the PG&E PPAs, subject to review by the bankruptcy court or, pursuant to a January 2019 FERC order (which PG&E is challenging), the bankruptcy court and FERC. The PG&E bankruptcy is an event of default under the PG&E PPAs. Unless the lenders for the related project debt otherwise agree, distributions from the related projects to Con Edison Development will not be made during the pendency of the bankruptcy. At December 31, 2018, Con Edison’s consolidated balance sheet included $885 million of net non-utility plant relating to the PG&E Projects, $1,125 million of intangible assets relating to the PG&E PPAs, $292 million of net non-utility plant of additional projects that secure the related project debt and $1,050 million of non-recourse related project debt. See "Long-term Debt" in Note C. Con Edison has tested whether its net non-utility plant relating to the PG&E Projects and intangible assets relating to the PG&E PPAs has been impaired. The projected future cash flows used in the test reflected Con Edison’s expectation that the PG&E PPAs are not likely to be rejected in the PG&E bankruptcy. Based on the test, Con Edison has determined that there was no impairment. If, in the future, one or more of the PG&E PPAs is rejected in the PG&E bankruptcy or any such rejection becomes likely, there will be an impairment of the related intangible asset and could be an impairment of the related non-utility plant. The amount of any such impairment could be material. Recoverable Energy Costs The Utilities generally recover all of their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state public utility regulators. If the actual energy supply costs for a given month are more or less than the amounts billed to customers for that month, the difference in most cases is recoverable from or refundable to customers. Differences between actual and billed electric and steam supply costs and costs of its electric demand management programs are generally deferred for charge or refund to customers during the next billing cycle (normally within one or two months ). For the Utilities’ gas costs, differences between actual and billed gas costs during the 12-month period ending each August are charged or refunded to customers during a subsequent 12-month period. New York Independent System Operator (NYISO) The Utilities purchase electricity through the wholesale electricity market administered by the NYISO. The difference between purchased power and related costs initially billed to the Utilities by the NYISO and the actual cost of power subsequently calculated by the NYISO is refunded by the NYISO to the Utilities, or paid to the NYISO by the Utilities. The reconciliation payments or receipts are recoverable from or refundable to the Utilities’ customers. Certain other payments to or receipts from the NYISO are also subject to reconciliation, with shortfalls or amounts in excess of specified rate allowances recoverable from or refundable to customers. These include proceeds from the sale through the NYISO of transmission rights on CECONY’s transmission system (transmission congestion contracts or TCCs). Temporary Cash Investments Temporary cash investments are short-term, highly-liquid investments that generally have maturities of three months or less at the date of purchase. They are stated at cost, which approximates market. The Companies consider temporary cash investments to be cash equivalents. Investments Investments consist primarily of the investments of Con Edison Transmission and the Clean Energy Businesses that are accounted for under the equity method, and the fair value of the Utilities’ supplemental retirement income plan and deferred income plan assets. The following investment assets are included in the Companies' consolidated balance sheets at December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 CET Gas investment in Stagecoach Gas Services, LLC $948 $971 $— $— CET Gas investment in Mountain Valley Pipeline, LLC (a) 363 98 — — Supplemental retirement income plan assets (c) 326 330 301 301 Deferred income plan assets 75 73 75 73 CET Electric investment in New York Transco, LLC 52 53 — — Con Edison Development equity method investments (b) — 467 — — Other 2 9 9 9 Total investments $1,766 $2,001 $385 $383 (a) See Note U. (b) Upon completion of the acquisition of Sempra Solar Holdings, LLC in December 2018, Con Edison is accounting on a consolidated basis for certain jointly-owned renewable electric production projects that previously were accounted for as equity method investments. See Note U. (c) See Note E. Pension and Other Postretirement Benefits The accounting rules for retirement benefits require an employer to recognize an asset or liability for the overfunded or underfunded status of its pension and other postretirement benefit plans. For a pension plan, the asset or liability is the difference between the fair value of the plan’s assets and the projected benefit obligation. For any other postretirement benefit plan, the asset or liability is the difference between the fair value of the plan’s assets and the accumulated postretirement benefit obligation. The accounting rules generally require employers to recognize all unrecognized prior service costs and credits and unrecognized actuarial gains and losses in accumulated other comprehensive income/(loss) (OCI), net of tax. Such amounts will be adjusted as they are subsequently recognized as components of total periodic benefit cost or income pursuant to the current recognition and amortization provisions. For the Utilities’ pension and other postretirement benefit plans, regulatory accounting treatment is generally applied in accordance with the accounting rules for regulated operations. Unrecognized prior service costs or credits and unrecognized actuarial gains and losses are recorded to regulatory assets or liabilities, rather than OCI. See Notes E and F. The total periodic benefit costs are recognized in accordance with the accounting rules for retirement benefits. Investment gains and losses are recognized in expense over a 15 -year period and other actuarial gains and losses are recognized in expense over a 10 -year period, subject to the deferral provisions in the rate plans. In accordance with the Statement of Policy issued by the NYSPSC and its current electric, gas and steam rate plans, CECONY defers for payment to or recovery from customers the difference between such expenses and the amounts for such expenses reflected in rates. Generally, O&R also defers such difference pursuant to its rate plans. See Note B. The Companies calculate the expected return on pension and other postretirement benefit plan assets by multiplying the expected rate of return on plan assets by the market-related value (MRV) of plan assets at the beginning of the year, taking into consideration anticipated contributions and benefit payments that are to be made during the year. The accounting rules allow the MRV of plan assets to be either fair value or a calculated value that recognizes changes in fair value in a systematic and rational manner over not more than five years. The Companies use a calculated value when determining the MRV of the plan assets that adjusts for 20 percent of the difference between fair value and expected MRV of plan assets. This calculated value has the effect of stabilizing variability in assets to which the Companies apply the expected return. Federal Income Tax In accordance with accounting rules for income taxes, the Companies have recorded an accumulated deferred federal income tax liability at current tax rates for temporary differences between the book and tax basis of assets and liabilities. In accordance with rate plans, the Utilities have recovered amounts from customers for a portion of the tax liability they will pay in the future as a result of the reversal or “turn-around” of these temporary differences. As to the remaining deferred tax liability, the Utilities had established regulatory assets for the net revenue requirements to be recovered from customers for the related future tax expense pursuant to the NYSPSC's 1993 Policy Statement approving accounting procedures consistent with accounting rules for income taxes and providing assurances that these future increases in taxes will be recoverable in rates. Upon enactment of the Tax Cuts and Jobs Act of 2017 on December 22, 2017 (the TCJA), the Companies re-measured their deferred tax assets and liabilities based upon the 21 percent corporate income tax rate under the TCJA. See “Other Regulatory Matters” and “Regulatory Assets and Liabilities” in Note B and Note L. Accumulated deferred investment tax credits are amortized ratably over the lives of the related properties and applied as a reduction to future federal income tax expense. Con Edison and its subsidiaries file a consolidated federal income tax return. The consolidated income tax liability is allocated to each member of the consolidated group using the separate return method. Each member pays or receives an amount based on its own taxable income or loss in accordance with a consolidated tax allocation agreement. Tax loss and tax credit carryforwards are allocated among members in accordance with consolidated tax return regulations. State Income Tax Con Edison and its subsidiaries file a combined New York State Corporation Business Franchise Tax Return. Similar to a federal consolidated income tax return, the income of all entities in the combined group is subject to New York State taxation, after adjustments for differences between federal and New York law and apportionment of income among the states in which the company does business. Each member’s share of the New York State tax is based on its own New York State taxable income or loss. Research and Development Costs Research and development costs are charged to operating expenses as incurred. Research and development costs were as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $24 $24 $24 CECONY 23 23 22 Reclassification Certain prior year amounts have been reclassified to conform with the current year presentation. Earnings Per Common Share Con Edison presents basic and diluted earnings per share on the face of its consolidated income statement. Basic earnings per share (EPS) are calculated by dividing earnings available to common shareholders (“Net income” on Con Edison’s consolidated income statement) by the weighted average number of Con Edison common shares outstanding during the period. In the calculation of diluted EPS, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for Con Edison consist of restricted stock units and deferred stock units for which the average market price of the common shares for the period was greater than the exercise price (see Note M) and its common shares that are subject to certain forward sale agreements (see Note C). Before the issuance of common shares upon settlement of the forward sale agreements, the shares will be reflected in the company’s diluted earnings per share calculations using the treasury stock method. Under this method, the number of common shares used in calculating diluted earnings per share is deemed to be increased by the excess, if any, of the number of shares that would be issued upon physical settlement of the forward sale agreements over the number of shares that could be purchased by the company in the market (based on the average market price during the period) using the proceeds due upon physical settlement (based on the adjusted forward sale price at the end of the reporting period). Basic and diluted EPS for Con Edison are calculated as follows: For the Years Ended December 31, (Millions of Dollars, except per share amounts/Shares in Millions) 2018 2017 2016 Net income $1,382 $1,525 $1,245 Weighted average common shares outstanding – basic 311.7 307.1 300.4 Add: Incremental shares attributable to effect of potentially dilutive securities 1.2 1.7 1.5 Adjusted weighted average common shares outstanding – diluted 312.9 308.8 301.9 Net Income per common share – basic $4.43 $4.97 $4.15 Net Income per common share – diluted $4.42 $4.94 $4.12 The computation of diluted EPS for the year ended December 31, 2018 excludes immaterial amounts of performance share awards that were not included because of their anti-dilutive effect. Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Changes in Accumulated Other Comprehensive Income/(Loss) by Component Changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: (Millions of Dollars) Con Edison CECONY Accumulated OCI, net of taxes, at December 31, 2015 (a) $(34) $(9) OCI before reclassifications, net of tax of $(1) for Con Edison and CECONY 2 1 Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(3) and $(1) for Con Edison and CECONY, respectively (a)(b) 5 1 Total OCI, net of taxes, at December 31, 2016 7 2 Accumulated OCI, net of taxes, at December 31, 2016 (a) $(27) $(7) OCI before reclassifications, net of tax of $3 and $1 for Con Edison and CECONY, respectively (4) — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(3) and $(1) for Con Edison and CECONY, respectively (a)(b) 5 1 Total OCI, net of taxes, at December 31, 2017 1 1 Accumulated OCI, net of taxes, at December 31, 2017 (a) $(26) $(6) OCI before reclassifications, net of tax of $3 for Con Edison 4 — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(2) for Con Edison (a)(b) 6 1 Total OCI, net of taxes, at December 31, 2018 10 1 Accumulated OCI, net of taxes, at December 31, 2018 (a) $(16) $(5) (a) Tax reclassified from accumulated OCI is reported in the income tax expense line item of the consolidated income statement. (b) For the portion of unrecognized pension and other postretirement benefit costs relating to the Utilities, costs are recorded into, and amortized out of, regulatory assets and liabilities instead of OCI. The net actuarial losses and prior service costs recognized during the period are included in the computation of total periodic pension and other postretirement benefit cost. See Notes E and F. Reconciliation of Cash, Temporary Cash Investments and Restricted Cash On January 1, 2018, the Compa

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2018
Regulated Operations [Abstract]
Regulatory Matters	Regulatory Matters Rate Plans The Utilities provide service to New York customers according to the terms of tariffs approved by the NYSPSC. Tariffs for service to customers of Rockland Electric Company (RECO), O&R’s New Jersey regulated utility subsidiary, are approved by the New Jersey Board of Public Utilities (NJBPU). The tariffs include schedules of rates for service that limit the rates charged by the Utilities to amounts that recover from their customers costs approved by the regulator, including capital costs, of providing service to customers as defined by the tariff. The tariffs implement rate plans adopted by state utility regulators in rate orders issued at the conclusion of rate proceedings. Pursuant to the Utilities’ rate plans, there generally can be no change to the charges to customers during the respective terms of the rate plans other than specified adjustments provided for in the rate plans. The Utilities’ rate plans each cover specified periods, but rates determined pursuant to a plan generally continue in effect until a new rate plan is approved by the state utility regulator. Common provisions of the Utilities’ New York rate plans include: Recoverable energy costs that allow the Utilities to recover on a current basis the costs for the energy they supply with no mark-up to their full-service customers. Cost reconciliations that reconcile pension and other postretirement benefit costs, environmental remediation costs, property taxes, variable rate tax-exempt debt and certain other costs to amounts reflected in delivery rates for such costs. In addition, changes in the Utilities' costs not reflected in rates, in excess of certain amounts, resulting from changes in tax or other law, rule, regulation, order, or other requirement or interpretation are deferred as a regulatory asset or regulatory liability to be reflected in the Utilities' next rate plan or in a manner to be determined by the NYSPSC. See "Other Regulatory Matters," below. Also, the Utilities generally retain the right to petition for recovery or accounting deferral of extraordinary and material cost increases and provision is sometimes made for the utility to retain a share of cost reductions, for example, property tax refunds. Revenue decoupling mechanisms that reconcile actual energy delivery revenues to the authorized delivery revenues approved by the NYSPSC. The difference is accrued with interest for refund to, or recovery from customers, as applicable. Earnings sharing that require the Utilities to defer for customer benefit a portion of earnings over specified rates of return on common equity. There is no symmetric mechanism for earnings below specified rates of return on common equity. Negative revenue adjustments for failure to meet certain performance standards relating to service, reliability, safety and other matters. Positive revenue adjustments for achievement of performance standards related to achievement of clean energy goals, safety and other matters. Net utility plant reconciliations that require deferral as a regulatory liability of the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates. There is generally no symmetric mechanism if actual average net utility plant balances are more than amounts reflected in rates. Rate base , as reflected in the rate plans, is, in general, the sum of the Utilities’ net plant, working capital and certain regulatory assets less deferred taxes and certain regulatory liabilities. For each rate plan, the NYSPSC uses a forecast of the average rate base for each year that new rates would be in effect (“rate year”). Weighted average cost of capital is determined based on the authorized common equity ratio, return on common equity, cost of long-term debt and customer deposits reflected in each rate plan. For each rate plan, the revenues designed to provide the utility a return on invested capital for each rate year are determined by multiplying each utility rate base by its pre – tax weighted average cost of capital. The Utilities’ actual return on common equity will reflect their actual operations for each rate year, and may be more or less than the authorized return on equity reflected in their rate plans (and if more, may be subject to earnings sharing). The following tables contain a summary of the Utilities’ rate plans: CECONY – Electric Effective period January 2014 – December 2016 January 2017 – December 2019 (b) Base rate changes Yr. 1 – $(76.2) million (a) Yr. 1 – $195 million (c) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 and 2 – $(37) million (d) Yr. 1 – $84 million Other revenue sources Retention of $90 million of annual transmission congestion revenues. Retention of $75 million of annual transmission congestion revenues. In 2017 and 2018, the company recorded $13 million and $25 million of earnings adjustment mechanism incentives for energy efficiency, respectively. The company also achieved other incentives of $5 million in 2017 and 2018 that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $3 million for service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred for customer benefit $146 million, $98 million and $101 million of revenues, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs (e) Current rate recovery of purchased power and fuel costs. Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $400 million annually) if certain performance targets are not met. In 2014, the company recorded a $5 million negative revenue adjustment. In 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $57 million, $26 million and $68 million of net regulatory liabilities, respectively (f). Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes (f), municipal infrastructure support costs (g), the impact of new laws and environmental site investigation and remediation to amounts reflected in rates (h). Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $17,323 million Yr. 1 – $18,902 million Weighted average cost of capital (after-tax) Yr. 1 – 7.05 percent Yr. 1 – 6.82 percent Authorized return on common equity Yrs. 1 and 2 – 9.2 percent 9.0 percent Actual return on common equity Yr. 1 – 9.04 percent Yr. 1 – 9.30 percent Earnings sharing Most earnings above an annual earnings threshold of 9.8 percent for Yrs. 1 and 2 and 9.6 percent for Yr. 3 are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014 the company had no earnings above the threshold. Actual earnings were $44.4 million and $6.5 million above the threshold for 2015 and 2016, respectively. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred; this amount was amortized to $0 at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's electric rate plan for January 2017 through December 2019. If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , CECONY is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (c) The electric base rate increases are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. At the NYSPSC’s option, these increases are being implemented with increases of $199 million in each rate year. Base rates reflect recovery by the company of certain costs of its energy efficiency, system peak reduction and electric vehicle programs (Yr. 1 - $20.5 million ; Yr. 2 - $49 million ; and Yr. 3 - $107.5 million ) over a ten -year period, including the overall pre-tax rate of return on such costs. (d) Amounts reflect annual amortization of $107 million of the regulatory asset for deferred Superstorm Sandy and other major storm costs. The costs recoverable from customers were reduced by $4 million . The costs are no longer subject to NYSPSC staff review and the recovery of the costs is no longer subject to refund. In 2016, an additional $123 million of net regulatory liabilities were amortized to income. (e) For transmission service provided pursuant to the open access transmission tariff of PJM Interconnection LLC (PJM), unless and until changed by the NYSPSC, the company will recover all charges incurred associated with the transmission service. In April 2017, the transmission service terminated because CECONY did not exercise its option to continue the service. See "Other Regulatory Matters," below. (f) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points ( 5.0 , 7.5 or 10.0 basis points , depending on the year). (g) In general, if actual expenses for municipal infrastructure support (other than company labor) are below the amounts reflected in rates the company will defer the difference for credit to customers, and if the actual expenses are above the amount reflected in rates the company will defer for recovery from customers 80 percent of the difference subject to a maximum deferral of 30 percent of the amount reflected in rates. (h) In addition, amounts reflected in rates relating to the regulatory asset for future income tax and the excess deferred federal income tax liability are subject to reconciliation. The NYSPSC staff is to audit the regulatory asset and the tax liability. Differences resulting from the NYSPSC staff review will be deferred for NYSPSC determination of any amounts to be refunded or collected from customers. See "Other Regulatory Matters," below. In January 2019, CECONY filed a request with the NYSPSC for an electric rate increase of $485 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, storms, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 100 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism and the provisions pursuant to which the company recovers its purchased power and fuel costs from customers. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding electric rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $352 million and $263 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Gas Effective period January 2014 – December 2016 January 2017 - December 2019 (b) Base rate changes Yr. 1 – $(54.6) million (a) Yr. 1 – $(5) million (b) Amortizations to income of net regulatory (assets) and liabilities $4 million over three years Yr. 1 – $39 million Other revenue sources Retention of revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. The company retained $70 million, $66 million and $65 million of such revenues in 2014, 2015 and 2016, respectively. Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. In 2017 and 2018, the company achieved incentives of $7 million and $6 million, respectively that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $5 million for gas leak backlog, leak prone pipe and service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred $28 million, $54 million and $71 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $33 million in 2014, $44 million in 2015, and $56 million in 2016) if certain gas performance targets are not met. In 2014, 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if performance targets relating to service, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $38 million, $11 million, and $32 million of net regulatory liabilities, respectively. (c) Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes, municipal infrastructure support costs, the impact of new laws and environmental site investigation and remediation to amounts reflected in rates. (d) Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $3,521 million Yr. 1 – $4,841 million Weighted average cost of capital Yr. 1 – 7.10 percent Yr. 1 – 6.82 percent Authorized return on common equity 9.3 percent 9.0 percent Actual return on common equity Yr. 1 – 8.02 percent Yr. 1 – 9.22 percent Earnings sharing Most earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014, 2015 and 2016, the company had no earnings above the threshold. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred which resulted in a $32 million regulatory liability at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's gas rate plan for January 2017 through December 2019. The gas base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity (d) See footnotes (e), (f), (g) and (h) to the table under "CECONY - Electric" above. In January 2019, CECONY filed a request with the NYSPSC for a gas rate increase of $210 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 70 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism (RDM) and provisions pursuant to which the company recovers its purchased gas costs from customers. Within the filing, the company is proposing to change the gas RDM from a revenue per customer methodology to a revenue per class methodology. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding gas rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $138 million and $155 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Steam Effective period January 2014 – December 2016 (a) Base rate changes Yr. 1 – $(22.4) million (b) Amortizations to income of net regulatory (assets) and liabilities $37 million over three years Recoverable energy costs Current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $1 million annually) if certain steam performance targets are not met. In 2014, 2015, 2016 and 2017 and 2018, the company did not record any negative revenue adjustments. Cost reconciliations (c) In 2014, 2015, 2016 2017 and 2018, the company deferred $42 million of net regulatory liabilities, $17 million of net regulatory assets, $8 million and $14 million of net regulatory liabilities, and $1 million of net regulatory assets, respectively. Net utility plant reconciliations Target levels reflected in rates were: Average rate base Yr. 1 – $1,511 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Authorized return on common equity 9.3 percent Actual return on common equity Yr. 1 – 9.82 percent Earnings sharing Weather normalized earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. Cost of long-term debt Yr. 1 – 5.17 percent Common equity ratio 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) The impact of these base rate changes was deferred which resulted in an $8 million regulatory liability at December 31, 2016. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity. In November 2018, O&R, the staff of the NYSPSC and other parties entered into a Joint Proposal for new electric and gas rate plans for the three-year period January 2019 through December 2021 (the Joint Proposal). The Joint Proposal is subject to NYSPSC approval. The following tables contain a summary of the current and proposed rate plans. O&R New York – Electric Effective period November 2015 - October 2017 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $9.3 million Yr. 1 – $13.4 million (e) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 – $(8.5) million (b) Yr. 1 – $(1.5) million (f) Other revenue sources Potential earnings adjustment mechanism incentives for peak reduction, energy efficiency, Distributed Energy Resources utilization and other potential incentives of up to: Yr. 1 - $3.6 million; Yr. 2 - $4.0 million; and Yr. 3 - $4.2 million. Revenue decoupling mechanisms In 2015, 2016, 2017 and 2018, the company deferred for the customer’s benefit an immaterial amount, $6.3 million as regulatory liabilities, $11.2 million as regulatory asset and $0.5 million as regulatory asset, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power costs. Continuation of current rate recovery of purchased power costs. Negative revenue adjustments Potential penalties (up to $4 million annually) if certain performance targets are not met. In 2015 the company recorded $1.25 million in negative revenue adjustments. In 2016, 2017 and 2018, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability and other matters are not met: Yr. 1 - $4.4 million; Yr. 2 - $4.4 million; and Yr. 3 - $4.5 million. Cost reconciliations In 2015, 2016 and 2017, the company deferred $0.3 million, $7.4 million and $3.2 million as net decreases to regulatory assets, respectively. In 2018, the company deferred $5 million as a net regulatory asset. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), major storms, the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $763 million Yr. 1 – $878 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 10.8 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $6.1 million, $0.3 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) $59.3 million of the regulatory asset for deferred storm costs is to be recovered from customers over a five year period, including $11.85 million in each of years 1 and 2, $1 million of the regulatory asset for such costs will not be recovered from customers, and all outstanding issues related to Superstorm Sandy and other past major storms prior to November 2014 are resolved. Approximately $4 million of regulatory assets for property tax and interest rate reconciliations will not be recovered from customers. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes electric AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $1 million in year 1 and $9 million in year 2. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with increases of: Yr. 1 - $8.6 million ; Yr. 2 - $12.1 million ; and Yr. 3 - $12.2 million . (f) Reflects amortization of, among other things, the Company’s net benefits under the TCJA prior to January 1, 2019, amortization of net regulatory liability for future income taxes and reduction of previously incurred regulatory assets for environmental remediation costs. Also, for electric, reflects amortization over a six year period of previously incurred incremental major storm costs. See "Other Regulatory Matters," below. (g) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points impact on return on common equity: Yr. 1 - 10.0 basis points; Yr. 2 - 7.5 basis points; and Yr. 3 - 5.0 basis points. (h) Energy efficiency costs are expensed as incurred. Such costs are subject to a downward-only reconciliation over the terms of the electric and gas rate plans. The Company will defer for the benefit of customers any cumulative shortfall over the terms of the electric and gas rate plans between actual expenditures and the levels provided in rates. (i) In addition, amounts reflected in rates relating to income taxes and excess deferred federal income tax liability balances will be reconciled (i.e., refunded to or collected from customers) to any final, non-appealable NYSPSC-ordered findings in its investigation of O&R’s income tax accounting. See “Other Regulatory Matters,” in Note B. (j) Net plant reconciliation for AMI expenditures will be implemented for a single category of AMI capital expenditures that includes amounts allocated to both electric and gas customers. O&R New York – Gas Effective period November 2015 – October 2018 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $16.4 million – $16.4 million – $5.8 million – $10.6 million collected through a surcharge Yr. 1 – $(7.5) million (e) Amortization to income of net regulatory (assets) and liabilities Yr. 1 – $(1.7) million (b) – $(2.1) million (b) – $(2.5) million (b) Yr. 1 – $1.8 million (f) Other revenue sources Continuation of retention of annual revenues from non-firm customers of up to $4.0 million, with variances to be shared 80 percent by customers and 20 percent by company . Revenue decoupling mechanisms In 2015, 2016 2017 and 2018, the company deferred $0.8 million of regulatory assets, $6.2 million of regulatory liabilities, $1.7 million of regulatory liabilities and $6.3 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $3.7 million in Yr. 1, $4.7 million in Yr. 2 and $4.9 million in Yr. 3) if certain performance targets are not met. In 2015, 2016 and 2017, the company did not record any negative revenue adjustments. In 2018, the company recorded a $0.1 million negative revenue adjustment. Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $5.5 million; Yr. 2 - $5.7 million; and Yr. 3 - $6.0 million. Cost reconciliations In 2015 and 2016, the company deferred $4.5 million and $6.6 million as net regulatory liabilities and assets, respectively. In 2017 and 2018, the company deferred $3.5 million and $7.4 million as net regulatory liabilities, respectively. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $366 million Yr. 1 – $454 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 11.2 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $4 million, $0.2 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) Reflects that the company will not recover from customers a total of approximately $14 million of regulatory assets for property tax and interest rate reconciliations. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes gas AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $0.5 million in year 1, $4.2 million in year 2 and $7.2 million in year 3. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with changes of: Yr. 1 - $(5.9) million ; Yr. 2 - $1.0 million ; and Yr. 3 - $1.0 million . Footnotes (f) through (j) to this table are the same as footnotes (f) through (j) to the table under “O&R New York - Electric,” above. RECO Effective period August 2014 – February 2017 March 2017 (a) Base rate changes Yr. 1 – $13.0 million Yr. 1 – $1.7 million Amortization to income of net regulatory (assets) and liabilities $0.4 million over three years and $(25.6) million of deferred storm costs over four years $0.2 million over three years and continuation of $(25.6) million of deferred storm costs over four years which expired on July 31, 2018 (b) Recoverable energy costs Current rate recovery of purchased power costs. Current rate recovery of purchased power costs. Cost reconciliations None None Average rate base $172.2 million Yr. 1 – $178.7 million Weighted average cost of capital (after-tax) 7.83 percent 7.47 percent Authorized return on common equity 9.75 percent 9.6 percent Actual return on common equity Yr. 1 – 9.2 percent Yr. 1 – 7.5 percent Cost of long-term debt 5.89 percent 5.37 percent Common equity ratio 50 percent 49.7 percent (a) Effective until a new rate plan approved by the NJBPU goes into effect. (b) In January 2016, the NJBPU approved RECO’s plan to spend $15.7 million in capital over three years to harden its electric system against storms, the costs of which RECO, beginning in 2017, is collecting through a customer surcharge. In November 2017, FERC approved a September 2017 settlement agreement among RECO, the New Jersey Division of Rate Counsel and the NJBPU that increases RECO's annual transmission revenue requirement from $11.8 million to $17.7 million , effective April 2017. The revenue requirement reflects a return on common equity of 10.0 percent . Other Regulatory Matters In August and November 2017, the NYSPSC issued orders in its proceeding investigating an April 21, 2017 Metr

Capitalization

Capitalization	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Capitalization	Capitalization Common Stock At December 31, 2018 and 2017 , Con Edison owned all of the issued and outstanding shares of common stock of the Utilities, the Clean Energy Businesses and Con Edison Transmission. CECONY owns 21,976,200 shares of Con Edison stock, which it purchased prior to 2001 in connection with Con Edison’s stock repurchase plan. CECONY presents in the financial statements the cost of the Con Edison stock it owns as a reduction of common shareholder’s equity. In November 2018, Con Edison entered into forward sale agreements relating to 14,973,492 shares of its common stock. In December 2018, the company issued 9,324,123 shares for $705 million upon physical settlement of shares subject to the forward sale agreements, to fund, in part, payment of the purchase price for the acquisition by a Con Edison Development subsidiary of Sempra Solar Holdings LLC. See Note U. At December 31, 2018, 5,649,369 shares remain subject to the forward sale agreements. The company expects the remaining shares under the forward sale agreements to settle by December 27, 2019. The company or the forward purchasers may accelerate the forward sale agreements upon the occurrence of certain events. On a settlement date, if the company decides to physically settle, it will issue shares to the forward purchasers at the then-applicable forward sale price. The forward sale price is equal to $75.537 per share subject to adjustment on a daily basis based on a floating interest rate factor less a spread and will be subject to decrease by amounts related to expected dividends. The remaining shares under the forward sale agreements will be physically settled, unless the company elects cash or net share settlement (which it has the right to do, subject to certain conditions, other than in limited circumstances). In the event the company elects to cash settle or net share settle, the settlement amount will be generally related to (1)(a) the market value of the common stock during the unwind period under the forward sale agreement minus (b) the applicable forward sale price; multiplied by (2) the number of shares subject to such cash settlement or net share settlement. If this settlement amount is a negative number, the forward purchasers will pay the company the absolute value of that amount or deliver to the company a number of share having a value equal to the absolute value of such amount. If this settlement amount is a positive number, the company will pay the forward purchasers that amount or deliver to the forward purchasers a number of shares having a value equal to such amount. Capitalization of Con Edison The outstanding capitalization for each of the Companies is shown on its Consolidated Statement of Capitalization, and for Con Edison includes outstanding debt of the Utilities and the Clean Energy Businesses. Dividends In accordance with NYSPSC requirements, the dividends that the Utilities generally pay are limited to not more than 100 percent of their respective income available for dividends calculated on a two – year rolling average basis. Excluded from the calculation of “income available for dividends” are non-cash charges to income resulting from accounting changes or charges to income resulting from significant unanticipated events. The restriction also does not apply to dividends paid in order to transfer to Con Edison proceeds from major transactions, such as asset sales, or to dividends reducing each utility subsidiary’s equity ratio to a level appropriate to its business risk. Long-term Debt Long-term debt maturing in the period 2019 - 2023 is as follows: (Millions of Dollars) Con Edison CECONY 2019 $650 $475 2020 866 350 2021 1,260 640 2022 413 — 2023 293 — CECONY has issued $450 million of tax – exempt debt through the New York State Energy Research and Development Authority (NYSERDA) that currently bear interest at a rate determined weekly and is subject to tender by bondholders for purchase by the company. The carrying amounts and fair values of long-term debt at December 31, 2018 and 2017 are: (Millions of Dollars) 2018 2017 Long-Term Debt (including current portion) (a) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $18,145 $18,740 $16,029 $18,147 CECONY $14,151 $14,685 $13,625 $15,163 (a) Amounts shown are net of unamortized debt expense and unamortized debt discount of $185 million and $139 million for Con Edison and CECONY, respectively, as of December 31, 2018 and $142 million and $121 million for Con Edison and CECONY, respectively, as of December 31, 2017 . The fair values of the Companies' long-term debt have been estimated primarily using available market information and at December 31, 2018 are classified as Level 2 (see Note P). At December 31, 2018 and 2017 , long – term debt of Con Edison included $2,076 million and $915 million , respectively, of non-recourse debt secured by the pledge of the applicable renewable energy production projects of the Clean Energy Businesses. As a result of the January 2019 PG&E bankruptcy (see "Long-Lived and Intangible Assets" in Note A), the company may be required to reclassify up to $1,050 million of such project debt to a current liability during the first quarter of 2019. The lenders for the $1,050 million of project debt may, upon written notice, declare principal and interest on the project debt to be due and payable immediately and, if such amounts are not timely paid, foreclose on the related projects. The company is seeking to negotiate agreements with the lenders pursuant to which the lenders would defer exercising these remedies. At December 31, 2018 and 2017 , long-term debt of Con Edison included $2 million and $7 million , respectively, of Transition Bonds issued in 2004 by O&R’s New Jersey utility subsidiary through a special purpose entity. Significant Debt Covenants The significant debt covenants under the financing arrangements for the Companies' debentures and Con Edison's notes and February 2019 $825 million , two -year variable-rate term loan include obligations to pay principal and interest when due and covenants not to consolidate with or merge into any other entity unless certain conditions are met. In addition, the notes include a covenant that the company shall continue its utility business in New York City, the term loan includes a covenant that, subject to certain exceptions, the company and its subsidiaries will not mortgage, lien, pledge or otherwise encumber its assets, and the notes and term loan provide that the company shall not permit its ratio of consolidated debt to consolidated total capital to exceed certain amounts ( 0.675 to 1 for the notes and 0.65 for the term loan) and include cross default provisions with respect to the failure by the company or any material subsidiary to make one or more payments in respect of material financial obligations (in excess of an aggregate $100 million of debt for the notes and $150 million of debt or derivative obligations for the term loan, excluding non-recourse debt) of the company (or any of its material subsidiaries, in the case of the notes) and the occurrence of an event or condition which results in the acceleration of the maturity of any material debt (in excess of an aggregate $100 million for the notes and $150 million for the term loan, not including non-recourse debt) of the company (or any of its material subsidiaries, in the case of the notes) or enables the holders of such debt to accelerate the maturity thereof. The Companies' debentures have no cross default provisions. The tax – exempt financing arrangements of CECONY are subject to covenants for the debentures discussed above and the covenants discussed below. The Companies were in compliance with their significant debt covenants at December 31, 2018 . The tax-exempt financing arrangements involved the issuance of uncollateralized promissory notes of CECONY to NYSERDA in exchange for the net proceeds of a like amount of tax – exempt bonds with substantially the same terms sold to the public by NYSERDA. The tax-exempt financing arrangements include covenants with respect to the tax – exempt status of the financing, including covenants with respect to the use of the facilities financed. The arrangements include provisions for the maintenance of liquidity and credit facilities, the failure to comply with which would, except as otherwise provided, constitute an event of default for the debt to which such provisions applied. The failure to comply with debt covenants would, except as otherwise provided, constitute an event of default for the debt to which such provisions applied. If an event of default were to occur, the principal and accrued interest on the debt to which such event of default applied and, in the case of the Con Edison notes, a make-whole premium might and, in the case of certain events of default would, become due and payable immediately. The liquidity and credit facilities currently in effect for the tax – exempt financing include covenants that the ratio of debt to total capital of CECONY will not at any time exceed 0.65 to 1 and that, subject to certain exceptions, CECONY will not mortgage, lien, pledge or otherwise encumber its assets. Certain of the facilities also include as events of default, defaults in payments of other debt obligations in excess of specified levels ( $150 million or $100 million , depending on the facility).

Short-Term Borrowing

Short-Term Borrowing	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Short-Term Borrowing	Short-Term Borrowing In December 2016, Con Edison and the Utilities entered into a credit agreement (Credit Agreement), under which banks are committed to provide loans and letters of credit on a revolving credit basis. The Credit Agreement expires in December 2022. There is a maximum of $2,250 million of credit available. The full amount is available to CECONY and $1,000 million (subject to increase up to $1,500 million ) is available to Con Edison, including up to $1,200 million of letters of credit. The Credit Agreement supports the Companies’ commercial paper programs. The Companies have not borrowed under the Credit Agreement. At December 31, 2018 , Con Edison had $1,741 million of commercial paper outstanding, of which $1,192 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2018 was 3.0 percent for both Con Edison and CECONY. At December 31, 2017 , Con Edison had $577 million of commercial paper outstanding of which $150 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2017 was 1.8 percent for both Con Edison and CECONY. At December 31, 2018 and 2017 , no loans were outstanding under the Credit Agreement. An immaterial amount of letters of credit were outstanding under the Credit Agreement as of December 31, 2018 and 2017 . The banks’ commitments under the Credit Agreement are subject to certain conditions, including that there be no event of default. The commitments are not subject to maintenance of credit rating levels or the absence of a material adverse change. Upon a change of control of, or upon an event of default by one of the Companies, the banks may terminate their commitments with respect to that company, declare any amounts owed by that company under the Credit Agreement immediately due and payable and require that company to provide cash collateral relating to the letters of credit issued for it under the Credit Agreement. Events of default for a company include that company exceeding at any time of a ratio of consolidated debt to consolidated total capital of 0.65 to 1 (at December 31, 2018 this ratio was 0.53 to 1 for Con Edison and 0.54 to 1 for CECONY); that company having liens on its assets in an aggregate amount exceeding five percent of its consolidated total capital, subject to certain exceptions; that company or any of its material subsidiaries failing to make one or more payments in respect of material financial obligations (in excess of an aggregate $150 million of debt or derivative obligations other than non-recourse debt) of that company; the occurrence of an event or condition which results in the acceleration of the maturity of any material debt (in excess of an aggregate $150 million of debt other than non-recourse debt) of that company or enables the holders of such debt to accelerate the maturity thereof; and other customary events of default. Interest and fees charged for the revolving credit facilities and any loans made or letters of credit issued under the Credit Agreement reflect the Companies’ respective credit ratings. The Companies were in compliance with their covenants at December 31, 2018 . In December 2018, Con Edison borrowed $825 million under a 6 -month variable-rate term loan to fund, in part, payment of the purchase price for the acquisition by a Con Edison Development subsidiary of Sempra Solar Holdings, LLC. See Note U. The company repaid the 6-month loan in February 2019 with borrowings under a two-year term loan agreement. See Note C. See Note S for information about short-term borrowing between related parties.

Pension Benefits

Pension Benefits	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Pension Benefits	Pension Benefits Con Edison maintains a tax-qualified, non-contributory pension plan that covers substantially all employees of CECONY, O&R and Con Edison Transmission and certain employees of the Clean Energy Businesses. The plan is designed to comply with the Internal Revenue Code and the Employee Retirement Income Security Act of 1974. Con Edison also maintains additional non – qualified supplemental pension plans. Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost – including administrative expenses $290 $263 $275 $272 $246 $258 Interest cost on projected benefit obligation 561 591 596 525 554 559 Expected return on plan assets (1,033) (968) (947) (979) (917) (898) Recognition of net actuarial loss 688 595 596 651 563 565 Recognition of prior service cost/(credit) (17) (17) 4 (19) (19) 2 TOTAL PERIODIC BENEFIT COST $489 $464 $524 $450 $427 $486 Cost capitalized (127) (181) (214) (119) (169) (203) Reconciliation to rate level (92) (34) 54 (100) (41) 58 Total expense recognized $270 $249 $364 $231 $217 $341 In March 2017, the FASB issued amendments to the guidance for retirement benefits through ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The Companies adopted ASU 2017-07 beginning on January 1, 2018. The guidance requires that components of net periodic benefit cost other than service cost be presented outside of operating income on consolidated income statements, and that only the service cost component is eligible for capitalization. Accordingly, the service cost components are included in the line "Other operations and maintenance" and the non-service cost components are included in the line “Other deductions” in the Companies' consolidated income statements. As permitted by a practical expedient under ASU 2017-07, the Companies applied the presentation requirements retrospectively for both pension and other postretirement benefit costs using amounts disclosed in prior-period financial statements as appropriate estimates. Funded Status The funded status at December 31, 2018 , 2017 and 2016 was as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN PROJECTED BENEFIT OBLIGATION Projected benefit obligation at beginning of year $15,536 $14,095 $14,377 $14,567 $13,203 $13,482 Service cost – excluding administrative expenses 286 259 271 267 241 254 Interest cost on projected benefit obligation 561 591 596 525 554 559 Net actuarial loss/(gain) (1,219) 1,231 (302) (1,159) 1,171 (282) Plan amendments — 6 (256) — — (259) Benefits paid (715) (646) (591) (658) (602) (551) PROJECTED BENEFIT OBLIGATION AT END OF YEAR $14,449 $15,536 $14,095 $13,542 $14,567 $13,203 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $14,274 $12,472 $11,759 $13,519 $11,815 $11,141 Actual return on plan assets (536) 2,041 829 (507) 1,935 787 Employer contributions 473 450 508 434 412 469 Benefits paid (715) (646) (591) (658) (602) (551) Administrative expenses (46) (43) (33) (44) (41) (31) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $13,450 $14,274 $12,472 $12,744 $13,519 $11,815 FUNDED STATUS $(999) $(1,262) $(1,623) $(798) $(1,048) $(1,388) Unrecognized net loss $2,464 $2,760 $3,157 $2,338 $2,624 $2,995 Unrecognized prior service costs (205) (223) (244) (222) (242) (258) Accumulated benefit obligation 13,030 13,897 12,655 12,161 12,972 11,806 The decrease in the pension liability at Con Edison and CECONY of $263 million and $250 million , respectively, compared with December 31, 2017 , was primarily due to a decrease in the plan’s projected benefit obligation as a result of an increase in the discount rate, partially offset by a decrease in plan assets as a result of the actual return on plan assets. For Con Edison, this decrease in pension liability corresponds with a decrease to regulatory assets of $273 million for unrecognized net losses and unrecognized prior service costs associated with the Utilities consistent with the accounting rules for regulated operations, a credit to OCI of $7 million (net of taxes) for the unrecognized net losses, and an immaterial change to OCI (net of taxes) for the unrecognized prior service costs associated with the Clean Energy Businesses, Con Edison Transmission, and RECO. For CECONY, the decrease in pension liability corresponds with a decrease to regulatory assets of $265 million for unrecognized net losses and unrecognized prior service costs consistent with the accounting rules for regulated operations, and also a credit to OCI of $1 million (net of taxes) for unrecognized net losses, and an immaterial change to OCI (net of taxes) for the unrecognized prior service costs associated with certain employees of the Clean Energy Businesses and Con Edison Transmission who previously worked for CECONY. A portion of the unrecognized net loss and prior service cost for the pension plan, equal to $512 million and $(17) million , respectively, will be recognized from accumulated OCI and the regulatory asset into net periodic benefit cost over the next year for Con Edison. Included in these amounts are $486 million and $(19) million , respectively, for CECONY. At December 31, 2018 and 2017 , Con Edison’s investments include $326 million and $330 million , respectively, held in external trust accounts for benefit payments pursuant to the supplemental retirement plans. Included in these amounts for CECONY were $301 million . See Note P. The accumulated benefit obligations for the supplemental retirement plans for Con Edison and CECONY were $316 million and $285 million as of December 31, 2018 and $331 million and $297 million as of December 31, 2017 , respectively. Assumptions The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount rate 4.25 % 3.70 % 4.25 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount rate 3.70 % 4.25 % 4.25 % Expected return on plan assets 7.50 % 7.50 % 7.80 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % The expected return assumption reflects anticipated returns on the plan’s current and future assets. The Companies’ expected return was based on an evaluation of the current environment, market and economic outlook, relationships between the economy and asset class performance patterns, and recent and long-term trends in asset class performance. The projections were based on the plan’s target asset allocation. Discount Rate Assumption To determine the assumed discount rate, the Companies use a model that produces a yield curve based on yields on selected highly rated (Aa or higher by either Moody’s or Standard & Poor’s) corporate bonds. Bonds with insufficient liquidity, bonds with questionable pricing information and bonds that are not representative of the overall market are excluded from consideration. For example, the bonds used in the model cannot be callable (with the exception of "make whole" callable bonds), and the amount of the bond issue outstanding must be in excess of $50 million . The spot rates defined by the yield curve and the plan’s projected benefit payments are used to develop a weighted average discount rate. Expected Benefit Payments Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years : (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $707 $726 $740 $755 $772 $4,072 CECONY 658 676 689 703 718 3,795 Expected Contributions Based on estimates as of December 31, 2018 , the Companies expect to make contributions to the pension plans during 2019 of $332 million (of which $301 million is to be made by CECONY). The Companies’ policy is to fund the total periodic benefit cost of the qualified plan to the extent tax deductible and to also contribute to the non-qualified supplemental plans. Plan Assets The asset allocations for the pension plan at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 45% - 55% 51 % 58 % 58 % Debt Securities 33% - 43% 39 % 33 % 33 % Real Estate 10% -14% 10 % 9 % 9 % Total 100% 100 % 100 % 100 % Con Edison has established a pension trust for the investment of assets to be used for the exclusive purpose of providing retirement benefits to participants and beneficiaries and payment of plan expenses. Pursuant to resolutions adopted by Con Edison’s Board of Directors, the Management Development and Compensation Committee of the Board of Directors (the Committee) has general oversight responsibility for Con Edison’s pension and other employee benefit plans. The pension plan’s named fiduciaries have been granted the authority to control and manage the operation and administration of the plans, including overall responsibility for the investment of assets in the trust and the power to appoint and terminate investment managers. The investment objectives of the Con Edison pension plan are to maintain a level and form of assets adequate to meet benefit obligations to participants, to achieve the expected long-term total return on the trust assets within a prudent level of risk and maintain a level of volatility that is not expected to have a material impact on the company’s expected contribution and expense or the company’s ability to meet plan obligations. The assets of the plan have no significant concentration of risk in one country (other than the United States), industry or entity. The strategic asset allocation is intended to meet the objectives of the pension plan by diversifying its funds across asset classes, investment styles and fund managers. An asset/liability study typically is conducted every few years to determine whether the current strategic asset allocation continues to represent the appropriate balance of expected risk and reward for the plan to meet expected liabilities. Each study considers the investment risk of the asset allocation and determines the optimal asset allocation for the plan. The target asset allocation for 2019 reflects the results of such a study conducted in 2018. Individual fund managers operate under written guidelines provided by Con Edison, which cover such areas as investment objectives, performance measurement, permissible investments, investment restrictions, trading and execution, and communication and reporting requirements. Con Edison management regularly monitors, and the named fiduciaries review and report to the Committee regarding, asset class performance, total fund performance, and compliance with asset allocation guidelines. Management changes fund managers and rebalances the portfolio as appropriate. At the direction of the named fiduciaries, such changes are reported to the Committee. Assets measured at fair value on a recurring basis are summarized below as defined by the accounting rules for fair value measurements (see Note P). The fair values of the pension plan assets at December 31, 2018 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,515 $10 $3,525 International Equity (b) 2,896 — 2,896 U.S. Government Issued Debt (c) — 1,886 1,886 Corporate Bonds Debt (d) — 2,619 2,619 Structured Assets Debt (e) — 6 6 Other Fixed Income Debt (f) — 121 121 Cash and Cash Equivalents (g) 160 556 716 Futures (h) 568 — 568 Total investments within the fair value hierarchy $7,139 $5,198 $12,337 Investments measured at NAV per share (n) Private Equity (i) 440 Real Estate (j) 1,310 Hedge Funds (k) 255 Total investments valued using NAV per share $2,005 Funds for retiree health benefits (l) (118) (86) (204) Funds for retiree health benefits measured at NAV per share (l)(n) (33) Total funds for retiree health benefits $(237) Investments (excluding funds for retiree health benefits) $7,021 $5,112 $14,105 Pending activities (m) (655) Total fair value of plan net assets $13,450 (a) U.S. Equity includes both actively- and passively-managed assets with investments in domestic equity index funds and actively-managed small-capitalization equities. (b) International Equity includes international equity index funds and actively-managed international equities. (c) U.S. Government Issued Debt includes agency and treasury securities. (d) Corporate Bonds Debt consists of debt issued by various corporations. (e) Structured Assets Debt includes commercial-mortgage-backed securities and collateralized mortgage obligations. (f) Other Fixed Income Debt includes municipal bonds, sovereign debt and regional governments. (g) Cash and Cash Equivalents include short term investments, money markets, foreign currency and cash collateral. (h) Futures consist of exchange-traded financial contracts encompassing U.S. Equity, International Equity and U.S. Government indices. (i) Private Equity consists of global equity funds that are not exchange-traded. (j) Real Estate investments include real estate funds based on appraised values that are broadly diversified by geography and property type. (k) Hedge Funds are within a commingled structure which invests in various hedge fund managers who can invest in all financial instruments. (l) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note F. (m) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received and reflects adjustments for available estimates at year end. (n) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair values of the pension plan assets at December 31, 2017 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,872 $28 $3,900 International Equity (b) 4,132 — 4,132 U.S. Government Issued Debt (c) — 1,786 1,786 Corporate Bonds Debt (d) — 2,450 2,450 Structured Assets Debt (e) — 3 3 Other Fixed Income Debt (f) — 125 125 Cash and Cash Equivalents (g) 124 352 476 Futures (h) 308 — 308 Total investments within the fair value hierarchy $8,436 $4,744 $13,180 Investments measured at NAV per share (n) Private Equity (i) 336 Real Estate (j) 1,214 Hedge Funds (k) 251 Total investments valued using NAV per share $1,801 Funds for retiree health benefits (l) (168) (94) (262) Funds for retiree health benefits measured at NAV per share (l)(n) (36) Total funds for retiree health benefits $(298) Investments (excluding funds for retiree health benefits) $8,268 $4,650 $14,683 Pending activities (m) (409) Total fair value of plan net assets $14,274 (a) - (n) Reference is made to footnotes (a) through (n) in the above table of pension plan assets at December 31, 2018 by asset category. The Companies also offer a defined contribution savings plan that covers substantially all employees and made contributions to the plan as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $45 $40 $36 CECONY 39 35 32

Other Postretirement Benefits

Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Other Postretirement Benefits	Other Postretirement Benefits The Utilities and Con Edison Transmission currently have contributory comprehensive hospital, medical and prescription drug programs for eligible retirees, their dependents and surviving spouses. CECONY also has a contributory life insurance program for bargaining unit employees and provides basic life insurance benefits up to a specified maximum at no cost to certain retired management employees. O&R has a non-contributory life insurance program for retirees. Certain employees of the Clean Energy Businesses and Con Edison Transmission are eligible to receive benefits under these programs. Total Periodic Benefit Cost The components of the Companies’ total periodic postretirement benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost $20 $20 $18 $14 $13 $13 Interest cost on accumulated other postretirement benefit obligation 42 46 48 34 38 40 Expected return on plan assets (73) (69) (77) (63) (61) (67) Recognition of net actuarial loss/(gain) 8 2 5 3 (3) 3 Recognition of prior service cost/(credit) (6) (17) (20) (2) (11) (14) TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT) $(9) $(18) $(26) $(14) $(24) $(25) Cost capitalized (8) 8 11 (6) 10 10 Reconciliation to rate level 8 (4) 22 9 (2) 22 Total expense/(credit) recognized $(9) $(14) $7 $(11) $(16) $7 For information about the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” see Note E. Funded Status The funded status of the programs at December 31, 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN BENEFIT OBLIGATION Benefit obligation at beginning of year $1,219 $1,198 $1,287 $985 $1,007 $1,093 Service cost 20 20 18 14 13 13 Interest cost on accumulated postretirement benefit obligation 42 46 48 34 38 40 Net actuarial loss/(gain) (70) 53 (57) (32) 16 (52) Benefits paid and administrative expenses, net of subsidies (135) (134) (134) (125) (124) (122) Participant contributions 38 36 36 37 35 35 BENEFIT OBLIGATION AT END OF YEAR $1,114 $1,219 $1,198 $913 $985 $1,007 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $1,039 $975 $994 $893 $851 $870 Actual return on plan assets (66) 150 60 (54) 130 52 Employer contributions 6 17 7 6 8 7 Employer group waiver plan subsidies 34 34 35 32 30 33 Participant contributions 37 35 36 37 35 35 Benefits paid (165) (172) (157) (155) (161) (146) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $885 $1,039 $975 $759 $893 $851 FUNDED STATUS $(229) $(180) $(223) $(154) $(92) $(156) Unrecognized net loss/(gain) $14 $(47) $(24) $(2) $(85) $(42) Unrecognized prior service costs (8) (14) (31) (5) (7) (18) The increase in the other postretirement benefits liability at Con Edison and CECONY of $49 million and $62 million , respectively, compared with December 31, 2017 , was primarily due to a decrease in plan assets as a result of the actual return on plan assets, partially offset by a decrease in the plans' projected benefit obligation as a result of an increase in the discount rate. For Con Edison, this increased liability corresponds with a decrease to regulatory liabilities of $70 million for unrecognized net losses and unrecognized prior service costs associated with the Utilities consistent with the accounting rules for regulated operations, a credit to OCI of $4 million (net of taxes) for the unrecognized net losses and a debit to OCI of $1 million (net of taxes) for the unrecognized prior service costs associated with the Clean Energy Businesses, Con Edison Transmission, and RECO. For CECONY, the increase in liability corresponds with a decrease to regulatory liabilities of $85 million for unrecognized net losses and unrecognized prior service costs associated with the company consistent with the accounting rules for regulated operations, and also a credit to OCI of $1 million (net of taxes) for the unrecognized net losses and an immaterial change to OCI (net of taxes) for the unrecognized prior service costs associated with certain employees of the Clean Energy Businesses and Con Edison Transmission who previously worked for CECONY. A portion of the unrecognized net losses and prior service costs for the other postretirement benefits, equal to $(7) million and $(2) million , respectively, will be recognized from accumulated OCI and the regulatory liability into net periodic benefit cost over the next year for Con Edison. Included in these amounts are $(10) million and $(2) million , respectively, for CECONY. Assumptions The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount Rate CECONY 4.15 % 3.55 % 4.00 % O&R 4.30 % 3.70 % 4.20 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount Rate CECONY 3.55 % 4.00 % 4.05 % O&R 3.70 % 4.20 % 4.20 % Expected Return on Plan Assets 7.50 % 7.50 % 7.00 % Refer to Note E for descriptions of the basis for determining the expected return on assets, investment policies and strategies and the assumed discount rate. The health care cost trend rate used to determine net periodic benefit cost for the year ended December 31, 2018 was 5.60 percent , which is assumed to decrease gradually to 4.50 percent by 2024 and remain at that level thereafter. The health care cost trend rate used to determine benefit obligations as of December 31, 2018 was 5.40 percent , which is assumed to decrease gradually to 4.50 percent by 2024 and remain at that level thereafter. A one-percentage point change in the assumed health care cost trend rate would have the following effects at December 31, 2018 : Con Edison CECONY 1-Percentage-Point (Millions of Dollars) Increase Decrease Increase Decrease Effect on accumulated other postretirement benefit obligation $9 $11 $(18) $31 Effect on service cost and interest cost components for 2018 2 (1) (1) 1 Expected Benefit Payments Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years , net of receipt of governmental subsidies: (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $80 $78 $76 $75 $74 $359 CECONY 70 67 65 64 63 302 Expected Contributions Based on estimates as of December 31, 2018 , Con Edison and CECONY expect to make a contribution of $10 million (of which $8 million is to be made by CECONY) to the other postretirement benefit plans in 2019 . The Companies’ policy is to fund the total periodic benefit cost of the plans to the extent tax deductible. Plan Assets The asset allocations for CECONY’s other postretirement benefit plans at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 42%-80% 52 % 60 % 60 % Debt Securities 20%-58% 48 % 40 % 40 % Total 100% 100 % 100 % 100 % Con Edison has established postretirement health and life insurance benefit plan trusts for the investment of assets to be used for the exclusive purpose of providing other postretirement benefits to participants and beneficiaries. Refer to Note E for a discussion of Con Edison’s investment policy for its benefit plans. The fair values of the plans' assets at December 31, 2018 by asset category as defined by the accounting rules for fair value measurements (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $322 $322 Other Fixed Income Debt (b) — 289 289 Cash and Cash Equivalents (c) — 14 14 Total investments $— $625 $625 Funds for retiree health benefits (d) 118 86 204 Investments (including funds for retiree health benefits) $118 $711 $829 Funds for retiree health benefits measured at net asset value (d)(e) 33 Pending activities (f) 23 Total fair value of plan net assets $885 (a) Equity includes a passively managed commingled index fund benchmarked to the MSCI All Country World Index. (b) Other Fixed Income Debt includes a passively managed commingled index fund benchmarked to the Bloomberg Barclays U.S. Long Credit Index and an active separately managed fund indexed to the Bloomberg Barclays U.S. Long Credit Index. (c) Cash and Cash Equivalents include short term investments and money markets. (d) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note E. (e) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (f) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received, and reflects adjustments for available estimates at year end. The fair values of the plans' assets at December 31, 2017 by asset category (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $420 $420 Other Fixed Income Debt (b) — 286 286 Cash and Cash Equivalents (c) — 16 16 Total investments $— $722 $722 Funds for retiree health benefits (d) 168 94 262 Investments (including funds for retiree health benefits) $168 $816 $984 Funds for retiree health benefits measured at net asset value (d)(e) 36 Pending activities (f) 19 Total fair value of plan net assets $1,039 (a) - (f) Reference is made to footnotes (a) through (f) in the above table of other postretirement benefit plan assets at December 31, 2018 by asset category.

Environmental Matters

Environmental Matters	12 Months Ended
	Dec. 31, 2018
Environmental Remediation Obligations [Abstract]
Environmental Matters	Environmental Matters Superfund Sites Hazardous substances, such as asbestos, polychlorinated biphenyls (PCBs) and coal tar, have been used or generated in the course of operations of the Utilities and their predecessors and are present at sites and in facilities and equipment they currently or previously owned, including sites at which gas was manufactured or stored. The Federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 and similar state statutes (Superfund) impose joint and several liability, regardless of fault, upon generators of hazardous substances for investigation and remediation costs (which include costs of demolition, removal, disposal, storage, replacement, containment and monitoring) and natural resource damages. Liability under these laws can be material and may be imposed for contamination from past acts, even though such past acts may have been lawful at the time they occurred. The sites at which the Utilities have been asserted to have liability under these laws, including their manufactured gas plant sites and any neighboring areas to which contamination may have migrated, are referred to herein as “Superfund Sites.” For Superfund Sites where there are other potentially responsible parties and the Utilities are not managing the site investigation and remediation, the accrued liability represents an estimate of the amount the Utilities will need to pay to investigate and, where determinable, discharge their related obligations. For Superfund Sites (including the manufactured gas plant sites) for which one of the Utilities is managing the investigation and remediation, the accrued liability represents an estimate of the company’s share of the undiscounted cost to investigate the sites and, for sites that have been investigated in whole or in part, the cost to remediate the sites, if remediation is necessary and if a reasonable estimate of such cost can be made. Remediation costs are estimated in light of the information available, applicable remediation standards and experience with similar sites. The accrued liabilities and regulatory assets related to Superfund Sites at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Accrued Liabilities: Manufactured gas plant sites $689 $651 $603 $551 Other Superfund Sites 90 86 90 86 Total $779 $737 $693 $637 Regulatory assets $810 $793 $716 $677 Most of the accrued Superfund Site liability relates to sites that have been investigated, in whole or in part. However, for some of the sites, the extent and associated cost of the required remediation has not yet been determined. As investigations progress and information pertaining to the required remediation becomes available, the Utilities expect that additional liability may be accrued, the amount of which is not presently determinable but may be material. The Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) prudently incurred site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Remediation costs incurred $25 $24 $18 $19 Insurance and other third party recoveries received by Con Edison or CECONY were immaterial in 2018 and 2017. Con Edison and CECONY estimate that in 2019 they will incur costs for remediation of approximately $28 million and $21 million , respectively. The Companies are unable to estimate the time period over which the remaining accrued liability will be incurred because, among other things, the required remediation has not been determined for some of the sites. In 2018 , Con Edison and CECONY estimated that for their manufactured gas plant sites (including CECONY’s Astoria site), the aggregate undiscounted potential liability for the investigation and remediation of coal tar and/or other environmental contaminants could range up to $2.8 billion and $2.6 billion , respectively. These estimates were based on the assumption that there is contamination at all sites, including those that have not yet been fully investigated and additional assumptions about the extent of the contamination and the type and extent of the remediation that may be required. Actual experience may be materially different. Asbestos Proceedings Suits have been brought in New York State and federal courts against the Utilities and many other defendants, wherein a large number of plaintiffs sought large amounts of compensatory and punitive damages for deaths and injuries allegedly caused by exposure to asbestos at various premises of the Utilities. The suits that have been resolved, which are many, have been resolved without any payment by the Utilities, or for amounts that were not, in the aggregate, material to them. The amounts specified in all the remaining thousands of suits total billions of dollars; however, the Utilities believe that these amounts are greatly exaggerated, based on the disposition of previous claims. At December 31, 2018 , Con Edison and CECONY have accrued their estimated aggregate undiscounted potential liabilities for these suits and additional suits that may be brought over the next 15 years as shown in the following table. These estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Courts have begun, and unless otherwise determined on appeal may continue, to apply different standards for determining liability in asbestos suits than the standard that applied historically. As a result, the Companies currently believe that there is a reasonable possibility of an exposure to loss in excess of the liability accrued for the suits. The Companies are unable to estimate the amount or range of such loss. In addition, certain current and former employees have claimed or are claiming workers’ compensation benefits based on alleged disability from exposure to asbestos. CECONY is permitted to defer as regulatory assets (for subsequent recovery through rates) costs incurred for its asbestos lawsuits and workers’ compensation claims. The accrued liability for asbestos suits and workers’ compensation proceedings (including those related to asbestos exposure) and the amounts deferred as regulatory assets for the Companies at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $79 $84 $75 $80 Regulatory assets – workers’ compensation $5 $10 $5 $10

Other Material Contingencies

Other Material Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Other Material Contingencies	10 years Total (Millions of Dollars) Con Edison Transmission $742 $404 $— $1,146 Energy transactions 462 20 201 683 Renewable electric production projects 137 — 403 540 Other 70 — — 70 Total $1,411 $424 $604 $2,439 Con Edison Transmission – Con Edison has guaranteed payment by CET Electric of the contributions CET Electric agreed to make to New York Transco LLC (NY Transco). CET Electric acquired a 45.7 percent interest in NY Transco when it was formed in 2014. In May 2016, the transmission owners transferred certain projects to NY Transco, for which CET Electric made its required contributions. NY Transco has proposed other transmission projects in the New York Independent System Operator's competitive bidding process. These other projects are subject to certain authorizations from the NYSPSC, the FERC and, as applicable, other federal, state and local agencies. Guarantee amount shown is for the maximum possible required amount of CET Electric's contributions for these other projects as calculated based on the assumptions that the projects are completed at 175 percent of their estimated costs and NY Transco does not use any debt financing for the projects. Guarantee term shown is assumed as the selection of the projects and resulting timing of the contributions is not certain. Also included within the table above are guarantees for $124 million from Con Edison on behalf of CET Gas in relation to Mountain Valley Pipeline (MVP), LLC, a company developing a proposed gas transmission project in West Virginia and Virginia. See Note U. Energy Transactions — Con Edison guarantees payments on behalf of the Clean Energy Businesses in order to facilitate physical and financial transactions in electricity, gas, pipeline capacity, transportation, oil, renewable energy credits and energy services. To the extent that liabilities exist under the contracts subject to these guarantees, such liabilities are included in Con Edison’s consolidated balance sheet. Renewable Electric Production Projects – Con Edison, Con Edison Development and Con Edison Solutions guarantee payments on behalf of their wholly-owned subsidiaries associated with their investment in, or development for others of, solar and wind energy facilities. See Note U. Other – Other guarantees include $70 million in guarantees provided by Con Edison to Travelers Insurance Company for indemnity agreements for surety bonds in connection with operation of solar energy facilities and energy service projects of Con Edison Development and Con Edison Solutions, respectively." id="sjs-B4">Other Material Contingencies Manhattan Explosion and Fire On March 12, 2014, two multi-use five-story tall buildings located on Park Avenue between 116th and 117th Streets in Manhattan were destroyed by an explosion and fire. CECONY had delivered gas to the buildings through service lines from a distribution main located below ground on Park Avenue. Eight people died and more than 50 people were injured. Additional buildings were also damaged. The National Transportation Safety Board (NTSB) investigated. The parties to the investigation included the company, the City of New York, the Pipeline and Hazardous Materials Safety Administration and the NYSPSC. In June 2015, the NTSB issued a final report concerning the incident, its probable cause and safety recommendations. The NTSB determined that the probable cause of the incident was (1) the failure of a defective fusion joint at a service tee (which joined a plastic service line to a plastic distribution main) installed by the company that allowed gas to leak from the distribution main and migrate into a building where it ignited and (2) a breach in a City sewer line that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the distribution main, which caused it to sag and overstressed the defective fusion joint. The NTSB also made safety recommendations, including recommendations to the company that addressed its procedures for the preparation and examination of plastic fusions, training of its staff on conditions for notifications to the City’s Fire Department and extension of its gas main isolation valve installation program. In February 2017, the NYSPSC approved a settlement agreement with the company related to the NYSPSC's investigations of the incident and the practices of qualifying persons to perform plastic fusions. Pursuant to the agreement, the company is providing $27 million of future benefits to customers (for which it has accrued a regulatory liability) and will not recover from customers $126 million of costs for gas emergency response activities that it had previously incurred and expensed. Approximately eighty suits are pending against the company seeking generally unspecified damages and, in some cases, punitive damages, for wrongful death, personal injury, property damage and business interruption. The company has notified its insurers of the incident and believes that the policies in force at the time of the incident will cover the company’s costs, in excess of a required retention (the amount of which is not material), to satisfy any liability it may have for damages in connection with the incident. The company is unable to estimate the amount or range of its possible loss for damages related to the incident. At December 31, 2018 , the company had not accrued a liability for damages related to the incident. Manhattan Steam Main Rupture In July 2018, a CECONY steam main located on Fifth Avenue and 21 st Street in Manhattan ruptured. Debris from the incident included dirt and mud containing asbestos. The response to the incident required the closing of buildings and streets for various periods. The NYSPSC has commenced an investigation. As of December 31, 2018 , with respect to the incident, the company incurred estimated operating costs of $14 million for property damage, clean-up and other response costs and invested $8 million in capital and retirement costs. The company has notified its insurers of the incident and believes that the policies currently in force will cover the company’s costs, in excess of a required retention (the amount of which is not material), to satisfy any liability it may have for damages to others in connection with the incident. The company is unable to estimate the amount or range of its possible loss related to the incident. At December 31, 2018 , the company had not accrued a liability related to the incident. Other Contingencies For information about the PG&E bankruptcy, see "Long-Lived and Intangible Assets" in Note A. Also, for additional contingencies, see “Other Regulatory Matters” in Note B and "Uncertain Tax Positions" in Note L. Guarantees Con Edison and its subsidiaries have entered into various agreements providing financial or performance assurance primarily to third parties on behalf of their subsidiaries. Maximum amounts guaranteed by Con Edison under these agreements totaled $2,439 million and $2,073 million at December 31, 2018 and 2017 , respectively. A summary, by type and term, of Con Edison’s total guarantees under these other agreements at December 31, 2018 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $742 $404 $— $1,146 Energy transactions 462 20 201 683 Renewable electric production projects 137 — 403 540 Other 70 — — 70 Total $1,411 $424 $604 $2,439 Con Edison Transmission – Con Edison has guaranteed payment by CET Electric of the contributions CET Electric agreed to make to New York Transco LLC (NY Transco). CET Electric acquired a 45.7 percent interest in NY Transco when it was formed in 2014. In May 2016, the transmission owners transferred certain projects to NY Transco, for which CET Electric made its required contributions. NY Transco has proposed other transmission projects in the New York Independent System Operator's competitive bidding process. These other projects are subject to certain authorizations from the NYSPSC, the FERC and, as applicable, other federal, state and local agencies. Guarantee amount shown is for the maximum possible required amount of CET Electric's contributions for these other projects as calculated based on the assumptions that the projects are completed at 175 percent of their estimated costs and NY Transco does not use any debt financing for the projects. Guarantee term shown is assumed as the selection of the projects and resulting timing of the contributions is not certain. Also included within the table above are guarantees for $124 million from Con Edison on behalf of CET Gas in relation to Mountain Valley Pipeline (MVP), LLC, a company developing a proposed gas transmission project in West Virginia and Virginia. See Note U. Energy Transactions — Con Edison guarantees payments on behalf of the Clean Energy Businesses in order to facilitate physical and financial transactions in electricity, gas, pipeline capacity, transportation, oil, renewable energy credits and energy services. To the extent that liabilities exist under the contracts subject to these guarantees, such liabilities are included in Con Edison’s consolidated balance sheet. Renewable Electric Production Projects – Con Edison, Con Edison Development and Con Edison Solutions guarantee payments on behalf of their wholly-owned subsidiaries associated with their investment in, or development for others of, solar and wind energy facilities. See Note U. Other – Other guarantees include $70 million in guarantees provided by Con Edison to Travelers Insurance Company for indemnity agreements for surety bonds in connection with operation of solar energy facilities and energy service projects of Con Edison Development and Con Edison Solutions, respectively.

Electricity Purchase Agreements

Electricity Purchase Agreements	12 Months Ended
	Dec. 31, 2018
Regulated Operations [Abstract]
Electricity Purchase Agreements	Regulatory Matters Rate Plans The Utilities provide service to New York customers according to the terms of tariffs approved by the NYSPSC. Tariffs for service to customers of Rockland Electric Company (RECO), O&R’s New Jersey regulated utility subsidiary, are approved by the New Jersey Board of Public Utilities (NJBPU). The tariffs include schedules of rates for service that limit the rates charged by the Utilities to amounts that recover from their customers costs approved by the regulator, including capital costs, of providing service to customers as defined by the tariff. The tariffs implement rate plans adopted by state utility regulators in rate orders issued at the conclusion of rate proceedings. Pursuant to the Utilities’ rate plans, there generally can be no change to the charges to customers during the respective terms of the rate plans other than specified adjustments provided for in the rate plans. The Utilities’ rate plans each cover specified periods, but rates determined pursuant to a plan generally continue in effect until a new rate plan is approved by the state utility regulator. Common provisions of the Utilities’ New York rate plans include: Recoverable energy costs that allow the Utilities to recover on a current basis the costs for the energy they supply with no mark-up to their full-service customers. Cost reconciliations that reconcile pension and other postretirement benefit costs, environmental remediation costs, property taxes, variable rate tax-exempt debt and certain other costs to amounts reflected in delivery rates for such costs. In addition, changes in the Utilities' costs not reflected in rates, in excess of certain amounts, resulting from changes in tax or other law, rule, regulation, order, or other requirement or interpretation are deferred as a regulatory asset or regulatory liability to be reflected in the Utilities' next rate plan or in a manner to be determined by the NYSPSC. See "Other Regulatory Matters," below. Also, the Utilities generally retain the right to petition for recovery or accounting deferral of extraordinary and material cost increases and provision is sometimes made for the utility to retain a share of cost reductions, for example, property tax refunds. Revenue decoupling mechanisms that reconcile actual energy delivery revenues to the authorized delivery revenues approved by the NYSPSC. The difference is accrued with interest for refund to, or recovery from customers, as applicable. Earnings sharing that require the Utilities to defer for customer benefit a portion of earnings over specified rates of return on common equity. There is no symmetric mechanism for earnings below specified rates of return on common equity. Negative revenue adjustments for failure to meet certain performance standards relating to service, reliability, safety and other matters. Positive revenue adjustments for achievement of performance standards related to achievement of clean energy goals, safety and other matters. Net utility plant reconciliations that require deferral as a regulatory liability of the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates. There is generally no symmetric mechanism if actual average net utility plant balances are more than amounts reflected in rates. Rate base , as reflected in the rate plans, is, in general, the sum of the Utilities’ net plant, working capital and certain regulatory assets less deferred taxes and certain regulatory liabilities. For each rate plan, the NYSPSC uses a forecast of the average rate base for each year that new rates would be in effect (“rate year”). Weighted average cost of capital is determined based on the authorized common equity ratio, return on common equity, cost of long-term debt and customer deposits reflected in each rate plan. For each rate plan, the revenues designed to provide the utility a return on invested capital for each rate year are determined by multiplying each utility rate base by its pre – tax weighted average cost of capital. The Utilities’ actual return on common equity will reflect their actual operations for each rate year, and may be more or less than the authorized return on equity reflected in their rate plans (and if more, may be subject to earnings sharing). The following tables contain a summary of the Utilities’ rate plans: CECONY – Electric Effective period January 2014 – December 2016 January 2017 – December 2019 (b) Base rate changes Yr. 1 – $(76.2) million (a) Yr. 1 – $195 million (c) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 and 2 – $(37) million (d) Yr. 1 – $84 million Other revenue sources Retention of $90 million of annual transmission congestion revenues. Retention of $75 million of annual transmission congestion revenues. In 2017 and 2018, the company recorded $13 million and $25 million of earnings adjustment mechanism incentives for energy efficiency, respectively. The company also achieved other incentives of $5 million in 2017 and 2018 that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $3 million for service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred for customer benefit $146 million, $98 million and $101 million of revenues, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs (e) Current rate recovery of purchased power and fuel costs. Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $400 million annually) if certain performance targets are not met. In 2014, the company recorded a $5 million negative revenue adjustment. In 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $57 million, $26 million and $68 million of net regulatory liabilities, respectively (f). Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes (f), municipal infrastructure support costs (g), the impact of new laws and environmental site investigation and remediation to amounts reflected in rates (h). Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $17,323 million Yr. 1 – $18,902 million Weighted average cost of capital (after-tax) Yr. 1 – 7.05 percent Yr. 1 – 6.82 percent Authorized return on common equity Yrs. 1 and 2 – 9.2 percent 9.0 percent Actual return on common equity Yr. 1 – 9.04 percent Yr. 1 – 9.30 percent Earnings sharing Most earnings above an annual earnings threshold of 9.8 percent for Yrs. 1 and 2 and 9.6 percent for Yr. 3 are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014 the company had no earnings above the threshold. Actual earnings were $44.4 million and $6.5 million above the threshold for 2015 and 2016, respectively. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred; this amount was amortized to $0 at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's electric rate plan for January 2017 through December 2019. If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , CECONY is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (c) The electric base rate increases are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. At the NYSPSC’s option, these increases are being implemented with increases of $199 million in each rate year. Base rates reflect recovery by the company of certain costs of its energy efficiency, system peak reduction and electric vehicle programs (Yr. 1 - $20.5 million ; Yr. 2 - $49 million ; and Yr. 3 - $107.5 million ) over a ten -year period, including the overall pre-tax rate of return on such costs. (d) Amounts reflect annual amortization of $107 million of the regulatory asset for deferred Superstorm Sandy and other major storm costs. The costs recoverable from customers were reduced by $4 million . The costs are no longer subject to NYSPSC staff review and the recovery of the costs is no longer subject to refund. In 2016, an additional $123 million of net regulatory liabilities were amortized to income. (e) For transmission service provided pursuant to the open access transmission tariff of PJM Interconnection LLC (PJM), unless and until changed by the NYSPSC, the company will recover all charges incurred associated with the transmission service. In April 2017, the transmission service terminated because CECONY did not exercise its option to continue the service. See "Other Regulatory Matters," below. (f) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points ( 5.0 , 7.5 or 10.0 basis points , depending on the year). (g) In general, if actual expenses for municipal infrastructure support (other than company labor) are below the amounts reflected in rates the company will defer the difference for credit to customers, and if the actual expenses are above the amount reflected in rates the company will defer for recovery from customers 80 percent of the difference subject to a maximum deferral of 30 percent of the amount reflected in rates. (h) In addition, amounts reflected in rates relating to the regulatory asset for future income tax and the excess deferred federal income tax liability are subject to reconciliation. The NYSPSC staff is to audit the regulatory asset and the tax liability. Differences resulting from the NYSPSC staff review will be deferred for NYSPSC determination of any amounts to be refunded or collected from customers. See "Other Regulatory Matters," below. In January 2019, CECONY filed a request with the NYSPSC for an electric rate increase of $485 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, storms, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 100 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism and the provisions pursuant to which the company recovers its purchased power and fuel costs from customers. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding electric rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $352 million and $263 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Gas Effective period January 2014 – December 2016 January 2017 - December 2019 (b) Base rate changes Yr. 1 – $(54.6) million (a) Yr. 1 – $(5) million (b) Amortizations to income of net regulatory (assets) and liabilities $4 million over three years Yr. 1 – $39 million Other revenue sources Retention of revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. The company retained $70 million, $66 million and $65 million of such revenues in 2014, 2015 and 2016, respectively. Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. In 2017 and 2018, the company achieved incentives of $7 million and $6 million, respectively that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $5 million for gas leak backlog, leak prone pipe and service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred $28 million, $54 million and $71 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $33 million in 2014, $44 million in 2015, and $56 million in 2016) if certain gas performance targets are not met. In 2014, 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if performance targets relating to service, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $38 million, $11 million, and $32 million of net regulatory liabilities, respectively. (c) Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes, municipal infrastructure support costs, the impact of new laws and environmental site investigation and remediation to amounts reflected in rates. (d) Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $3,521 million Yr. 1 – $4,841 million Weighted average cost of capital Yr. 1 – 7.10 percent Yr. 1 – 6.82 percent Authorized return on common equity 9.3 percent 9.0 percent Actual return on common equity Yr. 1 – 8.02 percent Yr. 1 – 9.22 percent Earnings sharing Most earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014, 2015 and 2016, the company had no earnings above the threshold. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred which resulted in a $32 million regulatory liability at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's gas rate plan for January 2017 through December 2019. The gas base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity (d) See footnotes (e), (f), (g) and (h) to the table under "CECONY - Electric" above. In January 2019, CECONY filed a request with the NYSPSC for a gas rate increase of $210 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 70 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism (RDM) and provisions pursuant to which the company recovers its purchased gas costs from customers. Within the filing, the company is proposing to change the gas RDM from a revenue per customer methodology to a revenue per class methodology. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding gas rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $138 million and $155 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Steam Effective period January 2014 – December 2016 (a) Base rate changes Yr. 1 – $(22.4) million (b) Amortizations to income of net regulatory (assets) and liabilities $37 million over three years Recoverable energy costs Current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $1 million annually) if certain steam performance targets are not met. In 2014, 2015, 2016 and 2017 and 2018, the company did not record any negative revenue adjustments. Cost reconciliations (c) In 2014, 2015, 2016 2017 and 2018, the company deferred $42 million of net regulatory liabilities, $17 million of net regulatory assets, $8 million and $14 million of net regulatory liabilities, and $1 million of net regulatory assets, respectively. Net utility plant reconciliations Target levels reflected in rates were: Average rate base Yr. 1 – $1,511 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Authorized return on common equity 9.3 percent Actual return on common equity Yr. 1 – 9.82 percent Earnings sharing Weather normalized earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. Cost of long-term debt Yr. 1 – 5.17 percent Common equity ratio 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) The impact of these base rate changes was deferred which resulted in an $8 million regulatory liability at December 31, 2016. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity. In November 2018, O&R, the staff of the NYSPSC and other parties entered into a Joint Proposal for new electric and gas rate plans for the three-year period January 2019 through December 2021 (the Joint Proposal). The Joint Proposal is subject to NYSPSC approval. The following tables contain a summary of the current and proposed rate plans. O&R New York – Electric Effective period November 2015 - October 2017 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $9.3 million Yr. 1 – $13.4 million (e) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 – $(8.5) million (b) Yr. 1 – $(1.5) million (f) Other revenue sources Potential earnings adjustment mechanism incentives for peak reduction, energy efficiency, Distributed Energy Resources utilization and other potential incentives of up to: Yr. 1 - $3.6 million; Yr. 2 - $4.0 million; and Yr. 3 - $4.2 million. Revenue decoupling mechanisms In 2015, 2016, 2017 and 2018, the company deferred for the customer’s benefit an immaterial amount, $6.3 million as regulatory liabilities, $11.2 million as regulatory asset and $0.5 million as regulatory asset, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power costs. Continuation of current rate recovery of purchased power costs. Negative revenue adjustments Potential penalties (up to $4 million annually) if certain performance targets are not met. In 2015 the company recorded $1.25 million in negative revenue adjustments. In 2016, 2017 and 2018, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability and other matters are not met: Yr. 1 - $4.4 million; Yr. 2 - $4.4 million; and Yr. 3 - $4.5 million. Cost reconciliations In 2015, 2016 and 2017, the company deferred $0.3 million, $7.4 million and $3.2 million as net decreases to regulatory assets, respectively. In 2018, the company deferred $5 million as a net regulatory asset. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), major storms, the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $763 million Yr. 1 – $878 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 10.8 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $6.1 million, $0.3 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) $59.3 million of the regulatory asset for deferred storm costs is to be recovered from customers over a five year period, including $11.85 million in each of years 1 and 2, $1 million of the regulatory asset for such costs will not be recovered from customers, and all outstanding issues related to Superstorm Sandy and other past major storms prior to November 2014 are resolved. Approximately $4 million of regulatory assets for property tax and interest rate reconciliations will not be recovered from customers. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes electric AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $1 million in year 1 and $9 million in year 2. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with increases of: Yr. 1 - $8.6 million ; Yr. 2 - $12.1 million ; and Yr. 3 - $12.2 million . (f) Reflects amortization of, among other things, the Company’s net benefits under the TCJA prior to January 1, 2019, amortization of net regulatory liability for future income taxes and reduction of previously incurred regulatory assets for environmental remediation costs. Also, for electric, reflects amortization over a six year period of previously incurred incremental major storm costs. See "Other Regulatory Matters," below. (g) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points impact on return on common equity: Yr. 1 - 10.0 basis points; Yr. 2 - 7.5 basis points; and Yr. 3 - 5.0 basis points. (h) Energy efficiency costs are expensed as incurred. Such costs are subject to a downward-only reconciliation over the terms of the electric and gas rate plans. The Company will defer for the benefit of customers any cumulative shortfall over the terms of the electric and gas rate plans between actual expenditures and the levels provided in rates. (i) In addition, amounts reflected in rates relating to income taxes and excess deferred federal income tax liability balances will be reconciled (i.e., refunded to or collected from customers) to any final, non-appealable NYSPSC-ordered findings in its investigation of O&R’s income tax accounting. See “Other Regulatory Matters,” in Note B. (j) Net plant reconciliation for AMI expenditures will be implemented for a single category of AMI capital expenditures that includes amounts allocated to both electric and gas customers. O&R New York – Gas Effective period November 2015 – October 2018 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $16.4 million – $16.4 million – $5.8 million – $10.6 million collected through a surcharge Yr. 1 – $(7.5) million (e) Amortization to income of net regulatory (assets) and liabilities Yr. 1 – $(1.7) million (b) – $(2.1) million (b) – $(2.5) million (b) Yr. 1 – $1.8 million (f) Other revenue sources Continuation of retention of annual revenues from non-firm customers of up to $4.0 million, with variances to be shared 80 percent by customers and 20 percent by company . Revenue decoupling mechanisms In 2015, 2016 2017 and 2018, the company deferred $0.8 million of regulatory assets, $6.2 million of regulatory liabilities, $1.7 million of regulatory liabilities and $6.3 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $3.7 million in Yr. 1, $4.7 million in Yr. 2 and $4.9 million in Yr. 3) if certain performance targets are not met. In 2015, 2016 and 2017, the company did not record any negative revenue adjustments. In 2018, the company recorded a $0.1 million negative revenue adjustment. Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $5.5 million; Yr. 2 - $5.7 million; and Yr. 3 - $6.0 million. Cost reconciliations In 2015 and 2016, the company deferred $4.5 million and $6.6 million as net regulatory liabilities and assets, respectively. In 2017 and 2018, the company deferred $3.5 million and $7.4 million as net regulatory liabilities, respectively. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $366 million Yr. 1 – $454 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 11.2 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $4 million, $0.2 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) Reflects that the company will not recover from customers a total of approximately $14 million of regulatory assets for property tax and interest rate reconciliations. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes gas AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $0.5 million in year 1, $4.2 million in year 2 and $7.2 million in year 3. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with changes of: Yr. 1 - $(5.9) million ; Yr. 2 - $1.0 million ; and Yr. 3 - $1.0 million . Footnotes (f) through (j) to this table are the same as footnotes (f) through (j) to the table under “O&R New York - Electric,” above. RECO Effective period August 2014 – February 2017 March 2017 (a) Base rate changes Yr. 1 – $13.0 million Yr. 1 – $1.7 million Amortization to income of net regulatory (assets) and liabilities $0.4 million over three years and $(25.6) million of deferred storm costs over four years $0.2 million over three years and continuation of $(25.6) million of deferred storm costs over four years which expired on July 31, 2018 (b) Recoverable energy costs Current rate recovery of purchased power costs. Current rate recovery of purchased power costs. Cost reconciliations None None Average rate base $172.2 million Yr. 1 – $178.7 million Weighted average cost of capital (after-tax) 7.83 percent 7.47 percent Authorized return on common equity 9.75 percent 9.6 percent Actual return on common equity Yr. 1 – 9.2 percent Yr. 1 – 7.5 percent Cost of long-term debt 5.89 percent 5.37 percent Common equity ratio 50 percent 49.7 percent (a) Effective until a new rate plan approved by the NJBPU goes into effect. (b) In January 2016, the NJBPU approved RECO’s plan to spend $15.7 million in capital over three years to harden its electric system against storms, the costs of which RECO, beginning in 2017, is collecting through a customer surcharge. In November 2017, FERC approved a September 2017 settlement agreement among RECO, the New Jersey Division of Rate Counsel and the NJBPU that increases RECO's annual transmission revenue requirement from $11.8 million to $17.7 million , effective April 2017. The revenue requirement reflects a return on common equity of 10.0 percent . Other Regulatory Matters In August and November 2017, the NYSPSC issued orders in its proceeding investigating an April 21, 2017 Metr

Leases

Leases	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Leases	Leases Con Edison’s subsidiaries lease electric transmission facilities, gas distribution facilities, land, office buildings and equipment. In accordance with the accounting rules for leases, these leases are classified as either capital leases or operating leases. Most of the operating leases provide the option to renew at the fair rental value for future periods. Capital leases: For ratemaking purposes capital leases are treated as operating leases; therefore, in accordance with the accounting rules for regulated operations, the amortization of the leased asset is based on the rental payments recovered from customers. The following assets under capital leases are included in the Companies’ consolidated balance sheets at December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 UTILITY PLANT Common $1 $2 $1 $1 The accumulated amortization of the capital leases for Con Edison and CECONY was $4 million and $2 million , respectively, at December 31, 2018 , and $3 million and $2 million , respectively, at December 31, 2017 . Operating leases: The future minimum lease commitments under the Companies’ operating lease agreements that are not cancellable by the Companies are as follows: (Millions of Dollars) Con Edison CECONY 2019 $72 $56 2020 72 56 2021 71 54 2022 68 53 2023 68 53 All years thereafter 890 592 Total $1,241 $864 Substantially all of the amounts shown in the above table for CECONY are estimated amounts payable under CECONY’s revocable consent agreement with New York City for the use of streets and public places for installation and operation of transformers and associated vaults and equipment. Under the agreement, payments by CECONY increase 2.18 percent annually and are subject to decrease if CECONY’s transformer installations decrease by ½ of 1 percent or more from the prior year. For information about changes to the accounting rules for leases adopted by the Companies in January 2019, see Note T.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill In 2018 and 2017, Con Edison elected to perform the optional qualitative assessment for goodwill related to the 1999 O&R merger and the gas storage company, and the first step of the quantitative test for the residential solar company. In 2018 and 2017 , Con Edison completed impairment tests for its goodwill of $406 million related to the O&R merger, and determined that it was not impaired. For the impairment test, $245 million and $161 million of goodwill were allocated to CECONY and O&R, respectively. In 2018 and 2017 , Con Edison completed impairment tests for goodwill of $8 million related to a gas storage company acquired by CET Gas from Con Edison Development and determined that it was not impaired. In 2016, Con Edison completed impairment tests for goodwill of $15 million related to two energy services companies owned by the Clean Energy Businesses and determined that goodwill was impaired and, upon calculating the implied fair value of goodwill using fair values based primarily on discounted cash flows, recorded a corresponding impairment charge of $15 million ( $12 million , net of tax). In 2018 and 2017 , Con Edison determined that goodwill of $14 million related to the residential solar company acquired by the Clean Energy Businesses in 2016 was not impaired. In 2018 the Clean Energy Businesses acquired a battery storage company and recorded $12 million of goodwill as part of the purchase price allocation. Estimates of future cash flows, projected growth rates, and discount rates inherent in the cash flow estimates for Con Edison subsidiaries other than the Utilities may vary significantly from actual results, which could result in a future impairment of goodwill.

Income Tax

Income Tax	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Tax	Income Tax The components of income tax are as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 State Current $(10) $(2) $(42) $6 $37 $(1) Deferred 107 103 188 82 75 114 Federal Current 3 (11) (43) (34) 73 59 Deferred 310 391 604 275 504 435 Amortization of investment tax credits (9) (9) (9) (3) (4) (4) Total income tax expense $401 $472 $698 $326 $685 $603 The tax effects of temporary differences, which gave rise to deferred tax assets and liabilities, are as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Deferred tax liabilities: Property basis differences $7,402 $6,555 $6,446 $5,968 Regulatory assets: Unrecognized pension and other postretirement costs 627 697 591 656 Environmental remediation costs 227 219 200 187 Deferred storm costs 21 11 — — Other regulatory assets 273 269 252 241 Equity investments 102 263 — — Total deferred tax liabilities $8,652 $8,014 $7,489 $7,052 Deferred tax assets: Accrued pension and other postretirement costs $248 $264 $180 $187 Regulatory liabilities: Future income tax 702 698 662 660 Other regulatory liabilities 632 593 554 524 Superfund and other environmental costs 218 203 194 176 Asset retirement obligations 114 86 82 79 Loss carryforwards 229 95 — — Tax credits carryforward 817 658 — — Valuation allowance (33) (33) — — Other 53 112 102 148 Total deferred tax assets 2,980 2,676 1,774 1,774 Net deferred tax liabilities $5,672 $5,338 $5,715 $5,278 Unamortized investment tax credits 148 157 24 28 Net deferred tax liabilities and unamortized investment tax credits $5,820 $5,495 $5,739 $5,306 The TCJA includes significant changes affecting the taxation of regulated public utilities, such as CECONY and O&R, and Con Edison’s other businesses. Substantially all of the provisions of the TCJA are effective for taxable years beginning after December 31, 2017. The TCJA reduced the corporate federal income tax rate from 35 percent to 21 percent . The TCJA provisions related to regulated public utilities generally allow for the continued deductibility of interest expense, do not allow for full expensing of certain property acquired after September 27, 2017, and continue certain rate normalization requirements for the tax benefit of accelerated depreciation. For most non-utility businesses, TCJA provides for full expensing of property acquired after September 27, 2017 and limits a deduction for interest expense to 30 percent of adjusted taxable income (which resembles earnings before interest, taxes, depreciation and amortization or “EBITDA”). In accordance with the accounting rules for income taxes (see “Federal Income Tax” in Note A), the tax effects of changes in tax laws are to be recognized in the period in which the law is enacted and deferred tax assets and liabilities are to be re-measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. For CECONY and O&R, in accordance with their New York rate plans and the accounting rules for regulated operations the change in deferred taxes was recorded as either an offset to a regulatory asset or a regulatory liability. See “Rate Plans” in Note B. For Con Edison’s other businesses, the change in deferred taxes was reflected as a decrease in income tax expense, which increased Con Edison's net income. Upon enactment of the TCJA in December 2017, the Companies re-measured their deferred tax assets and liabilities based upon the TCJA’s 21 percent corporate federal income tax rate. As a result, Con Edison, decreased its net deferred tax liabilities by $5,312 million (including $4,781 million for CECONY), recognized $259 million in net income, decreased its regulatory asset for future income tax by $1,250 million (including $1,182 million for CECONY), decreased the regulatory asset for revenue taxes by $90 million (including $86 million for CECONY), and accrued a regulatory liability for future income tax of $3,713 million (including $3,513 million for CECONY). Since the Companies are in a net regulatory liability position with respect to these income tax matters, the Companies netted the regulatory asset for future income tax against the regulatory liability for future income tax. Under the rate normalization requirements continued by the TCJA, $2,684 million of the net regulatory liability (including $2,542 million for CECONY) related to certain accelerated tax depreciation benefits is to be amortized over the remaining lives of the related assets. The remainder of the net regulatory liability is to be refunded (or credited) to customers as determined by the NYSPSC or NJBPU, as applicable. See “Other Regulatory Matters” in Note B. The amount recognized in net income included $269 million for the Clean Energy Businesses, $11 million for Con Edison Transmission and $(21) million for the parent company. The re-measurement had no impact on the Companies’ cash flows for 2017. At December 31, 2017, the Companies recorded provisional income tax amounts in its accounting for certain effects of the provisions of the TCJA as allowed under SEC Staff Accounting Bulletin 118 (SAB 118). SAB 118 allowed a one year period for companies to finalize the provisional amounts recorded as of December 31, 2017. In August 2018, the Internal Revenue Service (IRS) and U.S. Department of Treasury issued proposed regulations that clarified provisions in the TCJA on the allowance for additional first-year depreciation for qualified property of regulated public utilities placed in service in the fourth quarter of 2017. Under this guidance, which Con Edison elected to adopt, the Utilities deducted $477 million in additional depreciation in Con Edison’s 2017 federal income tax return. The additional depreciation increased Con Edison’s 2017 federal net operating loss (NOL) carryover to $563 million (CECONY’s 2017 federal NOL carryover of $153 million was applied in full to CECONY's 2018 tax liability), which required a re-measurement of deferred tax assets and liabilities associated with the filing of its 2017 federal income tax return. As a result, Con Edison decreased its net deferred tax liabilities by $13 million (including $50 million for CECONY), recognized $42 million in income tax expense at the parent company related to re-measuring the 2017 federal NOL carryover to 2018, decreased the regulatory asset for revenue taxes by $1 million (entirely attributable to CECONY) and accrued a regulatory liability for future income tax of $54 million (including $49 million for CECONY). The Companies completed their assessment in the fourth quarter of 2018 and no further adjustments to the provisional amounts were recorded. Reconciliation of the difference between income tax expense and the amount computed by applying the prevailing statutory income tax rate to income before income taxes is as follows: Con Edison CECONY (% of Pre-tax income) 2018 2017 2016 2018 2017 2016 STATUTORY TAX RATE Federal 21 % 35 % 35 % 21 % 35 % 35 % Changes in computed taxes resulting from: State income tax 4 4 4 5 4 4 Cost of removal 1 1 (1 ) 1 1 (1 ) Other plant-related items (1 ) (1 ) — (1 ) (1 ) (1 ) TCJA deferred tax re-measurement 2 (13 ) — — — — Amortization of excess deferred federal income taxes (3 ) — — (3 ) — — Renewable energy credits (1 ) (1 ) (1 ) — — — Research and development credits — — (1 ) (1 ) — (1 ) Other — (2 ) — (1 ) (1 ) — Effective tax rate 23 % 23 % 36 % 21 % 38 % 36 % CECONY and O&R deferred as regulatory liabilities their estimated net benefits under the TCJA for the year ended December 31, 2018. RECO deferred as a regulatory liability its estimated net benefits under the TCJA for the three months ended March 31, 2018. The net benefits include the revenue requirement impact of the reduction in the corporate federal income tax rate to 21 percent, the elimination for utilities of bonus depreciation and the amortization of excess deferred federal income taxes the utilities collected from customers that will not be paid to the IRS under the TCJA. See “Other Regulatory Matters” in Note B. Con Edison has a federal net operating loss carryover of approximately $711 million , due primarily to accelerated depreciation (including bonus depreciation). The 2017 federal net operating loss carryover of $520 million will expire, if unused, in 2037 and the 2018 federal net operating loss carryover of $191 million can be carried forward indefinitely. Con Edison has $817 million in general business tax credit carryovers (primarily renewable energy tax credits), which if unused will begin to expire in 2032. A deferred tax asset for these tax attribute carryforwards was recorded, and no valuation allowance has been provided, as it is more likely than not that the deferred tax asset will be realized. For New York State income tax purposes, Con Edison had a net operating loss of $97 million from 2017, primarily as a result of accelerated tax deductions on renewable energy projects. This loss was carried back to 2015 and will result in recovery of $9 million of income tax. In 2018, Con Edison had a New York State net operating loss of approximately $398 million , primarily as a result of accelerated tax deductions on renewable energy projects. Con Edison expects to carry back approximately $99 million of its 2018 net operating loss to 2015 and 2016, which will result in recovery of $9 million of income tax. The remaining 2018 New York State net operating loss of $299 million will be carried forward to future years. A deferred tax asset has been recognized for this New York State net operating loss that will expire, if unused, in 2038. A valuation allowance has not been provided; as it is more likely than not that the deferred tax asset will be realized. Charitable contributions carryforward of $5 million , $5 million , $7 million and $5 million for 2015, 2016, 2017 and 2018, respectively, will expire in 2020, 2021, 2022 and 2023, respectively. The carryforwards were recorded as a deferred tax asset, and no valuation allowance has been provided, as it is more likely than not that the deferred tax asset will be realized. In addition, a $12 million valuation allowance for New York City net operating loss carryforward and a $21 million valuation allowance for state net operating losses carryforward has been provided; as it is not more likely than not that the deferred tax asset will be realized. The Protecting Americans from Tax Hikes Act of 2015 extended bonus depreciation for property acquired and placed in service during 2015 through 2019. The bonus depreciation percentage is 50 percent for property placed in service during 2015, 2016 and 2017 and phases down to 40 percent in 2018, and 30 percent in 2019. Since Con Edison meets the de minimis exception set forth in the proposed Treasury regulations to qualify as a utility company for the consolidated group, the TCJA does not allow bonus depreciation for property acquired and placed in service by the Companies after December 31, 2017 (excluding the transition rules for incurred property costs prior to September 28, 2017 and subsequently placed in service in 2018 or 2019) . In August 2018, the Federal government issued proposed regulations providing guidance on provisions in the TCJA allowing for full expensing of qualified plant additions. These proposed regulations, which Con Edison adopted, allows Con Edison’s utilities a full expense tax deduction for plant additions in the fourth quarter of 2017, and the Utilities continue additional first year depreciation transition rules for plant additions placed in service in tax years beginning in 2018, under long-term construction contracts entered into before September 28, 2017. The impact on the Utilities of these regulations is discussed above. In November 2018, the Federal government issued, and Con Edison adopted, proposed regulations providing guidance on the tax deductibility of interest expense under the TCJA. The proposed regulations provide guidance on the treatment of consolidated interest expense. The regulations provide a safe harbor test that if at least 90% of consolidated plant assets consist of utility property, the entire consolidated group will be treated as a regulated public utility, and all of the consolidated group’s interest expense will be currently tax deductible. Qualifying consolidated groups would not be entitled to the full expensing provisions in the TCJA noted above. This safe harbor test must be met for each year in order to achieve a current tax deduction for consolidated interest expense. The safe harbor rules do not apply to partnerships in which Con Edison and its subsidiaries are a partner. Con Edison qualified for the safe harbor treatment in 2018. Uncertain Tax Positions Under the accounting rules for income taxes, the Companies are not permitted to recognize the tax benefit attributable to a tax position unless such position is more likely than not to be sustained upon examination by taxing authorities, including resolution of any related appeals and litigation processes, based solely on the technical merits of the position. A reconciliation of the beginning and ending amounts of unrecognized tax benefits for Con Edison and CECONY follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Balance at January 1, $12 $42 $34 $5 $21 $2 Additions based on tax positions related to the current year 2 1 2 2 1 2 Additions based on tax positions of prior years 1 1 19 1 1 19 Reductions for tax positions of prior years (2) (24) (13) (1) (18) (2) Reductions from expiration of statute of limitations (4) (2) — — — — Settlements (3) (6) — (3) — — Balance at December 31, $6 $12 $42 $4 $5 $21 In 2018, Con Edison reached a settlement with the IRS on tax years 2012 through 2016 and certain state statute of limitations expired which resulted in Con Edison reversing $9 million in uncertain tax positions. Of this amount, $6 million reduced Con Edison’s effective tax rate. The amount related to CECONY was $4 million , of which $1 million reduced CECONY’s effective tax rate. Current and prior year additions in 2018 are for tax credits. As of December 31, 2018 , Con Edison reasonably expects to resolve within the next twelve months approximately $4 million of various federal and state uncertainties due to the expected completion of ongoing tax examinations and resolution of state refund claims, of which the entire amount, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $2 million , of which the entire amount, if recognized, would reduce CECONY’s effective tax rate. The Companies recognize interest on liabilities for uncertain tax positions in interest expense and would recognize penalties, if any, in operating expenses in the Companies’ consolidated income statements. In 2018 , 2017 and 2016 , the Companies recognized an immaterial amount of interest and no penalties for uncertain tax positions in their consolidated income statements. At December 31, 2018 and 2017 , the Companies reflected an immaterial amount of interest and no penalties in their consolidated balance sheets. At December 31, 2018 , the total amount of unrecognized tax benefits that, if recognized, would reduce the Companies’ effective tax rate is $6 million with $4 million attributable to CECONY. Federal tax returns for 2017 remain under examination. State income tax returns remain open for examination in New York for tax years 2010 through 2017 and in New Jersey for tax years 2008 through 2017.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Companies may compensate employees and directors with, among other things, stock options, stock units, restricted stock units and contributions to the stock purchase plan. The Long Term Incentive Plan, which was approved by Con Edison’s shareholders in 2003 (2003 LTIP), and the Long Term Incentive Plan, which was approved by Con Edison’s shareholders in 2013 (2013 LTIP), are collectively referred to herein as the LTIP. The LTIP provides for, among other things, awards to employees of restricted stock units and stock options and, to Con Edison’s non-employee directors, stock units. Existing awards under the 2003 LTIP continue in effect, however no new awards may be issued under the 2003 LTIP. The 2013 LTIP provides for awards for up to five million shares of common stock. Shares of Con Edison common stock used to satisfy the Companies’ obligations with respect to stock-based compensation may be new (authorized, but unissued) shares, treasury shares or shares purchased in the open market. The shares used during the year ended December 31, 2018 were new shares. The Companies intend to use new shares to fulfill their stock-based compensation obligations for 2019 . The Companies recognized stock-based compensation expense using a fair value measurement method. The following table summarizes stock-based compensation expense recognized by the Companies in the years ended December 31, 2018 , 2017 and 2016 : Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Performance-based restricted stock $3 $53 $42 $3 $45 $36 Time-based restricted stock 2 2 2 1 2 2 Non-employee director deferred stock compensation 3 2 2 3 2 2 Stock purchase plan 6 6 4 6 6 4 Total $14 $63 $50 $13 $55 $44 Income tax benefit $4 $25 $20 $4 $22 $18 Stock Options The Companies last granted stock options in 2006. The stock options generally vested over a three -year period and had a term of 10 years. Options were granted at an exercise price equal to the fair market value of a common share when the option was granted. The Companies generally recognized compensation expense (based on the fair value of stock option awards) over the vesting period. At December 31, 2018 and 2017 , there were no outstanding options and no options were exercised. The income tax benefit Con Edison realized from stock options exercised in the year ended December 31, 2016 was $1 million . Restricted Stock and Stock Units Restricted stock and stock unit awards under the LTIP have been made as follows: (i) awards that provide for adjustment of the number of units (performance-restricted stock units or Performance RSUs) to certain officers and employees; (ii) time-based awards to certain employees; and (iii) awards to non-employee directors. Restricted stock and stock units awarded represents the right to receive, upon vesting, shares of Con Edison common stock, or, except for units awarded under the directors’ plan, the cash value of shares or a combination thereof. The number of units in each annual Performance RSU award is subject to adjustment as follows: (i) 50 percent of the units awarded will be multiplied by a factor that may range from 0 to 200 percent , based on Con Edison’s total shareholder return relative to a specified peer group during a specified performance period (the TSR portion); and (ii) 50 percent of the units awarded will be multiplied by factors that may range from 0 to 200 percent, based on determinations made in connection with the Companies’ annual incentive plans or, for certain executive officers, actual performance as compared to certain performance measures during a specified performance period (the non-TSR portion). Performance RSU awards generally vest upon completion of the performance period. Performance against the established targets is recomputed each reporting period as of the earlier of the reporting date and the vesting date. The TSR portion applies a Monte Carlo simulation model, and the non-TSR portion is the product of the market price at the end of the period and the average non-TSR determination over the vesting period. Performance RSUs are “liability awards” because each Performance RSU represents the right to receive, upon vesting, one share of Con Edison common stock, the cash value of a share or a combination thereof. As such, changes in the fair value of the Performance RSUs are reflected in net income. The assumptions used to calculate the fair value of the awards were as follows: 2018 2017 2016 Risk-free interest rate (a) 2.48% - 2.63% 1.76% - 1.89% 0.85% - 1.20% Expected term (b) 3 years 3 years 3 years Expected share price volatility (c) 14.76% - 17.71% 11.01% - 14.70% 17.72% - 18.22% (a) The risk-free rate is based on the U.S. Treasury zero-coupon yield curve. (b) The expected term of the Performance RSUs equals the vesting period. The Companies do not expect significant forfeitures to occur. (c) Based on historical experience. A summary of changes in the status of the Performance RSUs’ TSR and non-TSR portions during the year ended December 31, 2018 is as follows: Con Edison CECONY Weighted Average Grant Date Fair Value (a) Weighted Average Grant Date Fair Value (a) Units TSR Portion (b) Non-TSR Portion (c) Units TSR Portion (b) Non-TSR Portion (c) Non-vested at December 31, 2017 1,028,932 $71.74 $70.11 784,166 $71.06 $70.08 Granted 328,850 67.26 76.37 247,532 66.79 76.48 Vested (327,069) 57.77 63.27 (261,167) 57.37 63.18 Forfeited (24,877) 72.22 74.97 (20,877) 71.76 75.14 Transferred (d) — — — 12,252 78.47 72.71 Non-vested at December 31, 2018 1,005,836 $74.81 $74.27 761,906 $74.47 $74.42 (a) The TSR and non-TSR Portions each account for 50 percent of the awards’ value. (b) Fair value is determined using the Monte Carlo simulation described above. Weighted average grant date fair value does not reflect any accrual or payment of dividends prior to vesting. (c) Fair value is determined using the market price of one share of Con Edison common stock on the grant date. The market price has not been discounted to reflect that dividends do not accrue and are not payable on Performance RSUs until vesting. (d) Represents allocation to another Con Edison subsidiary of a portion of the Performance RSUs that had been awarded to a CECONY officer who transferred to another subsidiary. The total expense to be recognized by Con Edison in future periods for unvested Performance RSUs outstanding at December 31, 2018 is $21 million , including $18 million for CECONY, and is expected to be recognized over a weighted average period of one year for both Con Edison and CECONY. Con Edison and CECONY paid cash of $29 million and $28 million in 2018, $22 million and $21 million in 2017, and $21 million and $20 million in 2016, respectively, to settle vested Performance RSUs. In accordance with the accounting rules for stock compensation, for time-based awards, the Companies are accruing a liability and recognizing compensation expense based on the market value of a common share throughout the vesting period. The vesting period for awards is three years and is based on the employee’s continuous service to Con Edison. Prior to vesting, the awards are subject to forfeiture in whole or in part under certain circumstances. The awards are “liability awards” because each restricted stock unit represents the right to receive, upon vesting, one share of Con Edison common stock, the cash value of a share or a combination thereof. As such, prior to vesting, changes in the fair value of the units are reflected in net income. A summary of changes in the status of time-based awards during the year ended December 31, 2018 is as follows: Con Edison CECONY Units Weighted Average Grant Date Fair Value Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 64,870 $71.93 61,420 $71.93 Granted 23,000 77.94 21,400 77.94 Vested (20,523) 61.03 (19,473) 61.03 Forfeited (2,167) 73.93 (1,967) 73.97 Non-vested at December 31, 2018 65,180 $77.42 61,380 $77.42 The total expense to be recognized by Con Edison in future periods for unvested time-based awards outstanding at December 31, 2018 for Con Edison and CECONY was $2 million and is expected to be recognized over a weighted average period of one year . Con Edison and CECONY paid cash of $1 million in 2018, 2017 and 2016, to settle vested time-based awards. Under the LTIP, each non-employee director receives stock units, which are deferred until the director’s separation from service or another date specified by the director. Each director may also elect to defer all or a portion of their cash compensation into additional stock units, which are deferred until the director’s termination of service or another date specified by the director. Non-employee directors’ stock units issued under the LTIP are considered “equity awards,” because they may only be settled in shares. Directors immediately vest in units issued to them. The fair value of the units is determined using the closing price of Con Edison’s common stock on the business day immediately preceding the date of issue. In the year ended December 31, 2018 , approximately 33,100 units were issued at a weighted average grant date price of $76.08 . Stock Purchase Plan The Stock Purchase Plan, which was approved by shareholders in 2004 and 2014, provides for the Companies to contribute up to $1 for each $9 invested by their directors, officers or employees to purchase Con Edison common stock under the plan. Eligible participants may invest up to $25,000 during any calendar year (subject to an additional limitation for officers and employees of not more than 20 percent of their pay). Dividends paid on shares held under the plan are reinvested in additional shares unless otherwise directed by the participant. Participants in the plan immediately vest in shares purchased by them under the plan. The fair value of the shares of Con Edison common stock purchased under the plan was calculated using the average of the high and low composite sale prices at which shares were traded at the New York Stock Exchange on the trading day immediately preceding such purchase dates. During 2018 , 2017 and 2016 , 786,385 , 719,125 and 720,268 shares were purchased under the Stock Purchase Plan at a weighted average price of $78.27 , $79.57 and $72.67 per share, respectively.

Financial Information by Busine

Financial Information by Business Segment	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Financial Information by Business Segment	Financial Information by Business Segment The business segments of each of the Companies, which are its operating segments, were determined based on management’s reporting and decision-making requirements in accordance with the accounting rules for segment reporting. Con Edison’s principal business segments are CECONY’s regulated utility activities, O&R’s regulated utility activities, the Clean Energy Businesses and Con Edison Transmission. CECONY’s principal business segments are its regulated electric, gas and steam utility activities. All revenues of these business segments are from customers located in the United States of America. Also, all assets of the business segments are located in the United States of America. The accounting policies of the segments are the same as those described in Note A. Common services shared by the business segments are assigned directly or allocated based on various cost factors, depending on the nature of the service provided. The financial data for the business segments are as follows: As of and for the Year Ended December 31, 2018 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $7,971 $16 $984 $1,799 $(110) $519 $233 $31,012 $1,861 Gas 2,078 7 205 478 (23) 131 87 9,710 1,050 Steam 631 75 87 77 (10) 39 8 2,386 94 Consolidation adjustments — (98) — — — — — — — Total CECONY $10,680 $— $1,276 $2,354 ($143) $689 $328 $43,108 $3,005 O&R Electric $642 $— $56 $93 $(14) $25 $14 $2,036 $138 Gas 249 — 21 39 (5) 14 7 856 67 Other — — — — — — — — — Total O&R $891 $— $77 $132 $(19) $39 $21 $2,892 $205 Clean Energy Businesses $763 $— $85 $194 $33 $63 $19 $5,821 $1,791 Con Edison Transmission 4 — 1 (7) 91 20 (1) 1,425 248 Other (b) (1 ) — (1) (9) (24) 8 39 674 — Total Con Edison $12,337 $— $1,438 $2,664 $(62) $819 $406 $53,920 $5,249 As of and for the Year Ended December 31, 2017 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $7,972 $16 $925 $1,974 $(105) $472 $511 $29,661 $1,905 Gas 1,901 6 185 495 (23) 113 152 8,387 909 Steam 595 75 85 80 (9) 38 25 2,403 90 Consolidation adjustments — (97) — — — — — — — Total CECONY $10,468 $— $1,195 $2,549 $(137) $623 $688 $40,451 $2,904 O&R Electric $642 $— $51 $115 $(14) $24 $30 $1,949 $128 Gas 232 — 20 46 (5) 12 12 824 61 Other — — — — — — — — — Total O&R $874 $— $71 $161 $(19) $36 $42 $2,773 $189 Clean Energy Businesses $694 $— $74 $69 $33 $43 $(273) $2,735 $447 Con Edison Transmission 2 — 1 (8) 80 16 (11) 1,222 66 Other (b) (5) — — 3 (5) 11 13 930 — Total Con Edison $12,033 $— $1,341 $2,774 $(48) $729 $459 $48,111 $3,606 As of and for the Year Ended December 31, 2016 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $8,106 $17 $865 $1,996 $(147) $459 $495 $30,708 $1,819 Gas 1,508 6 159 387 (31) 105 92 7,553 811 Steam 551 88 82 68 (11) 39 30 2,595 126 Consolidation adjustments — (111) — — — — — — — Total CECONY $10,165 $— $1,106 $2,451 $(189) $603 $617 $40,856 $2,756 O&R Electric $637 $— $49 $107 $(11) $24 $30 $1,949 $114 Gas 184 — 18 39 (4) 12 10 809 52 Other — — — — — — — — — Total O&R $821 $— $67 $146 $(15) $36 $40 $2,758 $166 Clean Energy Businesses $1,091 $7 $42 $183 $21 $34 $53 $2,551 $1,235 Con Edison Transmission — — — (3) 43 6 — 1,150 1,078 Other (b) (2) (7) 1 3 (1) 17 4 940 — Total Con Edison $12,075 $— $1,216 $2,780 $(141) $696 $714 $48,255 $5,235 (a) For Con Edison, the income tax expense/(benefit) on non-operating income was $(5) million , $13 million and $(16) million in 2018 , 2017 and 2016 , respectively. For CECONY, the income tax expense/(benefit) on non-operating income was $(2) million , $(3) million and $(14) million in 2018 , 2017 and 2016 , respectively. At December 31, 2017, Con Edison re-measured its deferred tax assets and liabilities based upon the 21 percent corporate income tax rate under the TCJA. As a result, Con Edison, decreased its federal income tax expense by $259 million ( $269 million , $11 million and $(21) million , respectively, for the Clean Energy Businesses, Con Edison Transmission and the parent company). See “Other Regulatory Matters” in Note B and Note L to the financial statements in Item 8. (b) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Commodity Derivatives Con Edison’s subsidiaries hedge market price fluctuations associated with physical purchases and sales of electricity, natural gas, steam and, to a lesser extent, refined fuels by using derivative instruments including futures, forwards, basis swaps, options, transmission congestion contracts and financial transmission rights contracts. Derivatives are recognized on the consolidated balance sheet at fair value (see Note P), unless an exception is available under the accounting rules for derivatives and hedging. Qualifying derivative contracts that have been designated as normal purchases or normal sales contracts are not reported at fair value under the accounting rules. The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at December 31, 2018 and 2017 were: (Millions of Dollars) 2018 2017 Balance Sheet Location Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Con Edison Fair value of derivative assets Current $43 $(14) $29 (b) $83 $(51) $32 (b) Noncurrent 14 (7) 7 (c) 10 (4) 6 Total fair value of derivative assets $57 $(21) $36 (b)(c) $93 $(55) $38 Fair value of derivative liabilities Current $(61) $11 $(50) $(67) $50 $(17) Noncurrent (19) 9 (10) (c) (43) 5 (38) Total fair value of derivative liabilities $(80) $20 $(60) $(110) $55 $(55) Net fair value derivative assets/(liabilities) $(23) $(1) $(24) (b)(c) $(17) $— $(17) (b) CECONY Fair value of derivative assets Current $25 $(6) $19 (b) $39 $(15) $24 (b) Noncurrent 11 (5) 6 9 (4) 5 Total fair value of derivative assets $36 $(11) $25 $48 $(19) $29 Fair value of derivative liabilities Current $(31) $6 $(25) $(26) $14 $(12) Noncurrent (12) 6 (6) (36) 4 (32) Total fair value of derivative liabilities $(43) $12 $(31) $(62) $18 $(44) Net fair value derivative assets/(liabilities) $(7) $1 $(6) (b) $(14) $(1) $(15) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At December 31, 2018 and 2017 , margin deposits for Con Edison ( $7 million and $12 million , respectively) and CECONY ( $6 million and $11 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include interest rate swaps of $2 million in noncurrent assets and $(6) million in noncurrent liabilities (see below). The Utilities generally recover their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state utility regulators. See "Recoverable Energy Costs" in Note A. In accordance with the accounting rules for regulated operations, the Utilities record a regulatory asset or liability to defer recognition of unrealized gains and losses on their electric and gas derivatives. As gains and losses are realized in future periods, they will be recognized as purchased power, gas and fuel costs in the Companies’ consolidated income statements. The Clean Energy Businesses record realized and unrealized gains and losses on their derivative contracts in purchased power, gas purchased for resale and non-utility revenue in the reporting period in which they occur. Management believes that these derivative instruments represent economic hedges that mitigate exposure to fluctuations in commodity prices. The following table presents the realized and unrealized gains or losses on commodity derivatives that have been deferred or recognized in earnings for the years ended December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2018 2017 2018 2017 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(1) $3 $1 $4 Noncurrent Deferred derivative gains 4 — 3 — Total deferred gains/(losses) $3 $3 $4 $4 Current Deferred derivative losses $4 $51 $8 $49 Current Recoverable energy costs (26) (154) (26) (144) Noncurrent Deferred derivative losses 27 4 26 5 Total deferred gains/(losses) $5 $(99) $8 $(90) Net deferred gains/(losses) $8 $(96) $12 $(86) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $— $— $— $— Gas purchased for resale (2) 3 — — Non-utility revenue 4 (a) 5 (b) — — Other operations and maintenance expense (2) (c) — (2) — Total pre-tax gain/(loss) recognized in income $— $8 $(2) $— (a) For the year ended December 31, 2018 , Con Edison recorded unrealized pre-tax losses in non-utility operating revenue ( $5 million ). (b) For the year ended December 31, 2017 , Con Edison recorded an immaterial unrealized pre-tax gain in non-utility operating revenue. (c) For the year ended December 31, 2018 , Con Edison recorded unrealized pre-tax losses in other operations and maintenance expense ( $2 million ). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at December 31, 2018 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 28,303,678 18,519 164,668,697 3,780,000 CECONY 25,458,600 10,350 151,280,000 3,780,000 (a) Volumes are reported net of long and short positions, except natural gas collars where the volumes of long positions are reported. (b) Excludes electric congestion and gas basis swap contracts which are associated with electric and gas contracts and hedged volumes. The Companies are exposed to credit risk related to transactions entered into primarily for the various energy supply and hedging activities by the Utilities and the Clean Energy Businesses. Credit risk relates to the loss that may result from a counterparty’s nonperformance. The Companies use credit policies to manage this risk, including an established credit approval process, monitoring of counterparty limits, netting provisions within agreements, collateral or prepayment arrangements, credit insurance and credit default swaps. The Companies measure credit risk exposure as the replacement cost for open energy commodity and derivative positions plus amounts owed from counterparties for settled transactions. The replacement cost of open positions represents unrealized gains, net of any unrealized losses where the Companies have a legally enforceable right to offset. At December 31, 2018 , Con Edison and CECONY had $106 million and $13 million of credit exposure in connection with open energy supply net receivables and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $31 million with independent system operators, $28 million with investment-grade counterparties, $28 million with non-investment grade/non-rated counterparties, and $19 million with commodity exchange brokers. CECONY’s net credit exposure consisted of $7 million with investment-grade counterparties and $6 million with commodity exchange brokers. The collateral requirements associated with, and settlement of, derivative transactions are included in net cash flows from operating activities in the Companies’ consolidated statement of cash flows. Most derivative instrument contracts contain provisions that may require a party to provide collateral on its derivative instruments that are in a net liability position. The amount of collateral to be provided will depend on the fair value of the derivative instruments and the party’s credit ratings. The following table presents the aggregate fair value of the Companies’ derivative instruments with credit-risk-related contingent features that are in a net liability position, the collateral posted for such positions and the additional collateral that would have been required to be posted had the lowest applicable credit rating been reduced one level and to below investment grade at December 31, 2018 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $36 $24 Collateral posted 6 — Additional collateral (b) (downgrade one level from current ratings) 6 2 Additional collateral (b)(c) (downgrade to below investment grade from current ratings) 66 37 (a) Non-derivative transactions for the purchase and sale of electricity and gas and qualifying derivative instruments, which have been designated as normal purchases or normal sales, are excluded from the table. These transactions primarily include purchases of electricity from independent system operators. In the event the Utilities and the Clean Energy Businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $1 million at December 31, 2018 . For certain other such non-derivative transactions, the Companies could be required to post collateral under certain circumstances, including in the event counterparties had reasonable grounds for insecurity. (b) The Companies measure the collateral requirements by taking into consideration the fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liabilities position plus amounts owed to counterparties for settled transactions and amounts required by counterparties for minimum financial security. The fair value amounts represent unrealized losses, net of any unrealized gains where the Companies have a legally enforceable right to offset. (c) Derivative instruments that are net assets have been excluded from the table. At December 31, 2018 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $20 million . Interest Rate Swaps In December 2018, the Clean Energy Businesses acquired Sempra Solar Holding, LLC, which holds interest rate swaps that terminate in 2025, 2028 and 2035. The fair value of these interest rate swaps were a net liability of $5 million as of December 31, 2018 on Con Edison’s consolidated balance sheet. In December 2016, the Clean Energy Businesses acquired Coram Wind which holds an interest rate swap that terminates in June 2024, pursuant to which it pays a fixed-rate of 2.0855 percent and receives a LIBOR-based variable rate. The fair value of this interest rate swap was an asset of $1 million as of December 31, 2018 and immaterial as of December 31, 2017 on Con Edison’s consolidated balance sheet.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The accounting rules for fair value measurements and disclosures define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable firm inputs. The Companies often make certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. The Companies use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting rules for fair value measurements and disclosures established a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The rules require that assets and liabilities be classified in their entirety based on the level of input that is significant to the fair value measurement. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and their placement within the fair value hierarchy. The Companies classify fair value balances based on the fair value hierarchy defined by the accounting rules for fair value measurements and disclosures as follows: • Level 1 – Consists of assets or liabilities whose value is based on unadjusted quoted prices in active markets at the measurement date. An active market is one in which transactions for assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes contracts traded on active exchange markets valued using unadjusted prices quoted directly from the exchange. • Level 2 – Consists of assets or liabilities valued using industry standard models and based on prices, other than quoted prices within Level 1, that are either directly or indirectly observable as of the measurement date. The industry standard models consider observable assumptions including time value, volatility factors and current market and contractual prices for the underlying commodities, in addition to other economic measures. This category includes contracts traded on active exchanges or in over-the-counter markets priced with industry standard models. • Level 3 – Consists of assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost benefit constraints. This category includes contracts priced using models that are internally developed and contracts placed in illiquid markets. It also includes contracts that expire after the period of time for which quoted prices are available and internal models are used to determine a significant portion of the value. Assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2018 and 2017 are summarized below. 2018 2017 (Millions of Dollars) Level 1 Level 2 Level 3 Netting Adjustment (e) Total Level 1 Level 2 Level 3 Netting Adjustment (e) Total Con Edison Derivative assets: Commodity (a)(b)(c) $6 $36 $7 $(6) $43 $5 $77 $7 $(39) $50 Interest Rate Swaps (a)(b)(c)(f) — 2 — — 2 — — — — — Other (a)(b)(d) 287 114 — — 401 283 120 — — 403 Total assets $293 $152 $7 $(6) $446 $288 $197 $7 $(39) $453 Derivative liabilities: Commodity (a)(b)(c) $8 $43 $20 $(11) $60 $8 $93 $6 $(52) $55 Interest Rate Swaps (a)(b)(c)(f) — 6 — — 6 — — — — — Total liabilities $8 $49 $20 $(11) $66 $8 $93 $6 $(52) $55 CECONY Derivative assets: Commodity (a)(b)(c) $3 $28 $1 $(1) $31 $3 $40 $4 $(7) $40 Other (a)(b)(d) 267 109 — — 376 260 114 — — 374 Total assets $270 $137 $1 $(1) $407 $263 $154 $4 $(7) $414 Derivative liabilities: Commodity (a)(b)(c) $5 $30 $3 $(6) $32 $5 $57 $— $(18) $44 (a) The Companies’ policy is to review the fair value hierarchy and recognize transfers into and transfers out of the levels at the end of each reporting period. Con Edison and CECONY had $2 million of commodity derivative liabilities transferred from level 3 to level 2 during the year ended December 31, 2018 because of availability of observable market data due to the decrease in the terms of certain contracts from beyond three years as of December 31, 2017 to less than three years as of December 31, 2018 . Con Edison and CECONY had $11 million and $10 million , respectively, of commodity derivative liabilities transferred from level 3 to level 2 during the year ended December 31, 2017 because of availability of observable market data due to the decrease in the terms of certain contracts from beyond three years as of September 30, 2017 to less than three years as of December 31, 2017 . (b) Level 2 assets and liabilities include investments held in the deferred compensation plan and/or non-qualified retirement plans, exchange-traded contracts where there is insufficient market liquidity to warrant inclusion in Level 1, certain over-the-counter derivative instruments for electricity, refined products and natural gas. Derivative instruments classified as Level 2 are valued using industry standard models that incorporate corroborated observable inputs; such as pricing services or prices from similar instruments that trade in liquid markets, time value and volatility factors. (c) The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At December 31, 2018 and 2017 , the Companies determined that nonperformance risk would have no material impact on their financial position or results of operations. (d) Other assets are comprised of assets such as life insurance contracts within the deferred compensation plan and non-qualified retirement plans. (e) Amounts represent the impact of legally-enforceable master netting agreements that allow the Companies to net gain and loss positions and cash collateral held or placed with the same counterparties. (f) See Note O. The employees in the Companies’ risk management group develop and maintain the Companies’ valuation policies and procedures for, and verify pricing and fair value valuation of, commodity derivatives. Under the Companies’ policies and procedures, multiple independent sources of information are obtained for forward price curves used to value commodity derivatives. Fair value and changes in fair value of commodity derivatives are reported on a monthly basis to the Companies’ risk committees, comprised of officers and employees of the Companies that oversee energy hedging at the Utilities and the Clean Energy Businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at December 31, 2018 (Millions of Dollars) Valuation Techniques Unobservable Inputs Range Con Edison — Commodity Electricity $(12) Discounted Cash Flow Forward energy prices (a) $21.34-$64.45 per MWh Discounted Cash Flow Forward capacity prices (a) $1.00-$6.30 per kW-month Natural Gas (2) Discounted Cash Flow Forward natural gas prices (a) $0.92-$6.62 per Dt Transmission Congestion Contracts 1 Discounted Cash Flow Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.29-$8.03 per MWh Total Con Edison — Commodity $(13) CECONY — Commodity Electricity $(3) Discounted Cash Flow Forward capacity prices (a) $1.00-$6.30 per kW-month Transmission Congestion Contracts 1 Discounted Cash Flow Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.49-$2.60 per MWh Total CECONY — Commodity $(2) (a) Generally, increases (decreases) in this input in isolation would result in a higher (lower) fair value measurement. (b) Generally, increases (decreases) in this input in isolation would result in a lower (higher) fair value measurement. The table listed below provides a reconciliation of the beginning and ending net balances for assets and liabilities measured at fair value for the years ended December 31, 2018 and 2017 and classified as Level 3 in the fair value hierarchy: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Beginning balance as of January 1, $1 $1 $4 $1 Included in earnings 4 8 4 2 Included in regulatory assets and liabilities (10) (13) (4) (7) Purchases — 2 — 1 Settlements (6) (8) (4) (3) Transfer out of level 3 (2) 11 (2) 10 Ending balance as of December 31, $(13) $1 $(2) $4 For the Utilities, realized gains and losses on Level 3 commodity derivative assets and liabilities are reported as part of purchased power, gas and fuel costs. The Utilities generally recover these costs in accordance with rate provisions approved by the applicable state public utilities regulators. See Note A. Unrealized gains and losses for commodity derivatives are generally deferred on the consolidated balance sheet in accordance with the accounting rules for regulated operations. For the Clean Energy Businesses, realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues ( $3 million loss and $2 million gain) and purchased power costs ( immaterial ) on the consolidated income statement for the years ended December 31, 2018 and 2017 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at December 31, 2018 and 2017 is included in non-utility revenues ( $3 million loss and $2 million gain) and purchased power costs ( immaterial ) on the consolidated income statement for the years ended December 31, 2018 and 2017 , respectively.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities	Variable Interest Entities The accounting rules for consolidation address the consolidation of a variable interest entity (VIE) by a business enterprise that is the primary beneficiary. A VIE is an entity that does not have a sufficient equity investment at risk to permit it to finance its activities without additional subordinated financial support, or whose equity investors lack the characteristics of a controlling financial interest. The primary beneficiary is the business enterprise that has the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and either absorbs a significant amount of the VIE’s losses or has the right to receive benefits that could be significant to the VIE. The Companies enter into arrangements including leases, partnerships and electricity purchase agreements, with various entities. As a result of these arrangements, the Companies retain or may retain a variable interest in these entities. CECONY CECONY has an ongoing long-term electricity purchase agreement with Brooklyn Navy Yard Cogeneration Partners, LP, a potential VIE. In 2018, a request was made of this counterparty for information necessary to determine whether the entity was a VIE and whether CECONY is the primary beneficiary; however, the information was not made available. In April 2017, CECONY's long-term electricity purchase agreement with Cogen Technologies Linden Venture, LP (Linden Cogeneration), another potential VIE, expired. See Note I for information on these electricity purchase agreements, the payments pursuant to which constitute CECONY's maximum exposure to loss with respect to the potential VIEs. Con Edison Development Con Edison has a variable interest in OCI Solar San Antonio 4 LLC (Texas Solar 4), which is a consolidated entity in which Con Edison Development has an 80 percent membership interest. Con Edison is the primary beneficiary since the power to direct the activities that most significantly impact the economics of Texas Solar 4 is held by a Con Edison Development subsidiary. Texas Solar 4 owns a project company that developed a 40 MW (AC) solar electric production project. Electricity generated by the project is sold pursuant to a long-term power purchase agreement. At December 31, 2018 and 2017 , Con Edison’s consolidated balance sheet includes $27 million and $26 million in net assets (as detailed in the table below) respectively and the noncontrolling interest of the third party of $7 million related to Texas Solar 4. Con Edison's earnings from Texas Solar 4 for the years ended December 31, 2018 and 2017 were immaterial. In December 2018, a Con Edison Development subsidiary completed its acquisition of Sempra Solar Holdings, LLC. See Note U. Included in the acquisition were certain operating projects (Tax Equity Projects) with noncontrolling tax equity investors to which a percentage of earnings, tax attributes and cash flows are allocated. The Tax Equity Projects are consolidated entities in which Con Edison has less than a 100 percent membership interest. Con Edison is the primary beneficiary since the power to direct the activities that most significantly impact the economics of the Tax Equity Projects is held by Con Edison Development subsidiaries. Electricity generated by the Tax Equity Projects is sold to utilities and municipalities pursuant to long-term power purchase agreements. At December 31, 2018 , Con Edison’s consolidated balance sheet includes $870 million in net assets (as detailed in the table below) related to these Tax Equity Projects and the noncontrolling interest of the tax equity investors of $104 million . Con Edison's earnings from the Tax Equity Projects, accounted for under the hypothetical liquidation at book value (HLBV) method of accounting, for the year ended December 31, 2018 were immaterial. At December 31, 2018 and 2017 , Con Edison’s consolidated balance sheet included the following amounts associated with its VIEs: Tax Equity Projects Great Valley Solar Copper Mountain - Mesquite Solar Texas Solar 4 (Millions of Dollars) 2018 2018 2018 2017 Restricted cash $— $— $4 $5 Non-utility property, less accumulated depreciation of $1 for each of the Tax Equity Projects and $15 and $12, for Texas Solar 4 in 2018 and 2017, respectively 313 492 98 101 Other assets 18 97 9 8 Total assets (a) $331 $589 $111 $114 Long-term debt due within one year $— $— $2 $2 Other liabilities 17 33 26 28 Long-term debt — — 56 58 Total liabilities (b) $17 $33 $84 $88 (a) The assets of the Tax Equity Projects and Texas Solar 4 represent assets of a consolidated VIE that can be used only to settle obligations of the consolidated VIE. (b) The liabilities of the Tax Equity Projects and Texas Solar 4 represent liabilities of a consolidated VIE for which creditors do not have recourse to the general credit of the primary beneficiary. The following table summarizes the VIEs into which Con Edison Development has entered as of December 31, 2018 : Project Name Generating Capacity (a) (MW AC) Power Purchase Agreement Term in Years Year of Investment Location Maximum Millions of Dollars ) (b) Great Valley Solar (c) 200 15-20 2018 California $281 Copper Mountain - Mesquite Solar (d) 344 20-25 2018 Nevada and Arizona 485 Texas Solar 4 32 25 2014 Texas 20 (a) Represents Con Edison Development’s ownership interest in the project. (b) Maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest ( $33 million for Great Valley Solar, $71 million for Copper Mountain - Mesquite Solar and $7 million for Texas Solar 4). Con Edison did not provide any financial or other support during the year that was not previously contractually required. (c) Great Valley Solar consists of the Great Valley Solar 1, Great Valley Solar 2, Great Valley Solar 3 and Great Valley Solar 4 projects. (d) Copper Mountain - Mesquite Solar consists of the Copper Mountain Solar 4, Mesquite Solar 2 and Mesquite Solar 3 projects.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The Companies recognize a liability at fair value for legal obligations associated with the retirement of long-lived assets in the period in which they are incurred, or when sufficient information becomes available to reasonably estimate the fair value of such legal obligations. When the liability is initially recorded, asset retirement costs are capitalized by increasing the carrying amount of the related asset. The liability is accreted to its present value each period and the capitalized cost is depreciated over the useful life of the related asset. The fair value of the asset retirement obligation liability is measured using expected future cash flows discounted at credit-adjusted risk-free rates, historical information, and where available, quoted prices from outside contractors. The Companies evaluate these assumptions underlying the asset retirement obligation liability on an annual basis or as frequently as needed. The Companies recorded asset retirement obligations associated with the removal of asbestos and asbestos-containing material in their buildings (other than the structures enclosing generating stations and substations), electric equipment and steam and gas distribution systems. The Companies also recorded asset retirement obligations relating to gas and oil pipelines abandoned in place and municipal infrastructure support. The Companies did not record an asset retirement obligation for the removal of asbestos associated with the structures enclosing generating stations and substations. For these building structures, the Companies were unable to reasonably estimate their asset retirement obligations because the Companies were unable to estimate the undiscounted retirement costs or the retirement dates and settlement dates. The amount of the undiscounted retirement costs could vary considerably depending on the disposition method for the building structures, and the method has not been determined. The Companies anticipate continuing to use these building structures in their businesses for an indefinite period, and so the retirement dates and settlement dates are not determinable. Con Edison recorded asset retirement obligations for the removal of the Clean Energy Businesses’ solar and wind equipment related to projects located on property that is not owned by them and the term of the arrangement is finite including any renewal options. Con Edison did not record asset retirement obligations for the Clean Energy Businesses’ projects that are located on property that is owned by them because they expect that the equipment will continue to generate electricity at these facilities long past the manufacturer’s warranty at minimal operating expense. Therefore, Con Edison was unable to reasonably estimate the retirement date of this equipment. The Utilities include in depreciation rates the estimated removal costs, less salvage, for utility plant assets. The amounts related to removal costs that are associated with asset retirement obligations are classified as an asset retirement liability. Pursuant to accounting rules for regulated operations, future removal costs that do not represent legal asset retirement obligations are recorded as regulatory liabilities. Accretion and depreciation expenses related to removal costs that represent legal asset retirement obligations are applied against the Companies’ regulatory liabilities. Asset retirement costs that are recoverable from customers are recorded as regulatory liabilities to reflect the timing difference between costs recovered through the rate-making process and recognition of costs. At December 31, 2018 , the liabilities for asset retirement obligations of Con Edison and CECONY were $450 million and $292 million , respectively. At December 31, 2017 , the liabilities for asset retirement obligations of Con Edison and CECONY were $314 million and $287 million , respectively. The change in liabilities at December 31, 2018 was due to changes in estimated cash flows of $168 million and $39 million for Con Edison and CECONY, respectively, and accretion expense of $13 million and $11 million for Con Edison and CECONY, respectively. The changes were offset by liabilities settled of $45 million for both Con Edison and CECONY. Con Edison and CECONY also recorded reductions of $50 million and $36 million during the years ended December 31, 2018 and 2017 , respectively, to the regulatory liability associated with cost of removal to reflect depreciation and interest expense.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The NYSPSC generally requires that the Utilities and Con Edison’s other subsidiaries be operated as separate entities. The Utilities and the other subsidiaries are required to have separate operating employees and operating officers of the Utilities may not be operating officers of the other subsidiaries. The Utilities may provide administrative and other services to, and receive such services from, Con Edison and its other subsidiaries only pursuant to cost allocation procedures approved by the NYSPSC. Transfers of assets between the Utilities and Con Edison or its other subsidiaries may be made only as approved by the NYSPSC. The debt of the Utilities is to be raised directly by the Utilities and not derived from Con Edison. Without the prior permission of the NYSPSC, the Utilities may not make loans to, guarantee the obligations of, or pledge assets as security for the indebtedness of Con Edison or its other subsidiaries. The NYSPSC limits the dividends that the Utilities may pay Con Edison. See “Dividends” in Note C. As a result, substantially all of the net assets of CECONY and O&R ( $12,910 million and $712 million ), respectively, at December 31, 2018 are considered restricted net assets. The NYSPSC may impose additional measures to separate, or “ring fence,” the Utilities from Con Edison and its other subsidiaries. See “Rate Plans” in Note B. The costs of administrative and other services provided by CECONY to, and received by it from, Con Edison and its other subsidiaries for the years ended December 31, 2018 , 2017 and 2016 were as follows: CECONY (Millions of Dollars) 2018 2017 2016 Cost of services provided $115 $111 $108 Cost of services received 73 64 64 In addition, CECONY and O&R have joint gas supply arrangements, in connection with which CECONY sold to O&R $83 million , $66 million and $47 million of natural gas for the years ended December 31, 2018 , 2017 and 2016 , respectively. These amounts are net of the effect of related hedging transactions. The Utilities perform work and incur expenses on behalf of NY Transco, a company in which CET Electric has a 45.7 percent equity interest. The Utilities bill NY Transco for such work and expenses in accordance with established policies. For the year ended December 31, 2018 and 2017 , the amounts billed by the Utilities to NY Transco were immaterial. In May 2016, CECONY transferred certain electric transmission projects to NY Transco. CECONY has storage and wheeling service contracts with Stagecoach Gas Services LLC (Stagecoach), a joint venture formed by a subsidiary of CET Gas and a subsidiary of Crestwood Equity Partners LP (Crestwood). In addition, CECONY is the replacement shipper on one of Crestwood’s firm transportation agreements with Tennessee Gas Pipeline Company LLC. CECONY incurred costs for storage and wheeling services from Stagecoach of $28 million , $31 million and $18 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. In addition, the Clean Energy Businesses entered into two electricity sales agreements with Stagecoach under which the amounts received in 2018, 2017 and 2016 were immaterial. CECONY has a 20 -year transportation contract with Mountain Valley Pipeline, LLC (MVP) for 250,000 dekatherms per day of capacity. CET Gas holds a 12.5 percent equity interest in MVP. In October 2017, the Environmental Defense Fund and the Natural Resource Defense Council requested the NYSPSC to prohibit CECONY from recovering costs under its MVP contract unless CECONY can demonstrate that the contract is in the public interest. CECONY advised the NYSPSC that it would respond to the request if the NYSPSC opened a proceeding to consider this request. For the years ended December 31, 2018 and 2017 , CECONY incurred no costs under the contract. FERC has authorized CECONY through 2019 to lend funds to O&R from time to time, for periods of not more than 12 months , in amounts not to exceed $250 million outstanding at any time, at prevailing market rates. There were no outstanding loans to O&R at December 31, 2018 and 2017 . Con Edison Energy had financial electric capacity contracts with CECONY and O&R during 2018 and a contract with CECONY during 2017. For the years ended December 31, 2018 and 2017 , Con Edison Energy realized a $1 million loss and a $3 million gain, respectively, under these contracts.

New Financial Accounting Standa

New Financial Accounting Standards	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
New Financial Accounting Standards	New Financial Accounting Standards In January 2019, the Companies adopted Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842),” including the amendments thereto (the New Standard), using a modified retrospective transition method of adoption. The New Standard supersedes the lease requirements within Accounting Standard Codification (ASC) Topic 840, “Leases.” The New Standard requires lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Under the New Standard, lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The Utilities, as regulated entities, are permitted to continue to recognize expense using the timing that conforms to the regulatory rate treatment. Lessor accounting is similar to the previous model, but updated to align with “Revenue from Contracts with Customers (Topic 606)." Upon adoption of the New Standard, the Companies elected the following practical expedients: (1) for leases commenced prior to adoption date, the following three transition expedients that will allow the Companies to not reassess: (a) whether expired contracts contain leases; (b) the lease classification for expired leases and (c) the initial direct costs for existing leases; (2) for an underlying asset class, an expedient that allows the Companies to not apply the recognition requirements to short-term leases and an expedient that will allow the Companies to account for lease and associated non-lease components as a single lease component; (3) an expedient that allows the use of hindsight to determine lease term; and (4) an expedient that allows the Companies to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. For leases previously classified as operating leases, upon adoption of the New Standard, the Companies recognized on their balance sheets right-of-use assets and corresponding lease liabilities of approximately $875 million and $635 million for Con Edison and CECONY, respectively, as of January 1, 2019. The adoption of the New Standard will not have a material effect on the Companies’ liquidity or results of operations. The Companies will prepare additional disclosures as required by the New Standard beginning in 2019. The Companies implemented additional internal controls related to the New Standard, however the adoption of the New Standard is not expected to require a change that will materially affect the Companies’ internal control over financial reporting. In January 2017, the FASB issued amendments to the guidance for the subsequent measurement of goodwill through ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The amendments in this update simplify goodwill impairment testing by eliminating Step 2 of the goodwill impairment test wherein an entity has to compute the implied fair value of goodwill by performing procedures to determine the fair value of its assets and liabilities. Under the new guidance, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value up to the total amount of goodwill allocated to that reporting unit. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2017, the FASB issued amendments to the guidance for debt securities through ASU 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” The amendments in this update shorten the amortization period for certain callable debt securities held at a premium. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The application of this guidance will not have a material impact on the Companies’ financial position, results of operations and liquidity. In August 2017, the FASB issued amendments to the guidance for derivatives and hedging through ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this update provide greater clarification on hedge accounting for risk components, presentation and disclosure of hedging instruments, and overall targeted improvements to simplify hedge accounting. For public entities, the amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The application of the guidance will not have a material impact on the Companies’ financial position, results of operations and liquidity. In February 2018, the FASB issued amendments to the guidance for reporting comprehensive income through ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The amendments allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the TCJA. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Companies adopted the amendments in the fourth quarter of 2018. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial. In August 2018, the FASB issued amendments to the guidance for internal use software through ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract.” The amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Companies elected to adopt the amendments in the third quarter of 2018, prospectively for all in-scope implementation costs incurred after the date of adoption. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial.

Acquisitions, Investments and D

Acquisitions, Investments and Dispositions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisitions, Investments and Dispositions	Acquisitions, Investments and Dispositions Acquisitions and Investments Mountain Valley Pipeline In January 2016, CET Gas acquired a 12.5 percent equity interest in MVP, a company developing a proposed gas transmission project in West Virginia and Virginia. The company's initial contribution to MVP was $18 million . At December 31, 2018 and 2017 , CET Gas' investment in MVP was $363 million and $98 million , respectively. MVP has indicated that the project has an estimated total cost of $4,600 million and is targeted to be fully in-service during the fourth quarter of 2019. Con Edison is accounting for its equity interest in MVP as an equity method investment. Pilesgrove In June 2016, Con Edison Development recorded an $8 million ( $5 million , net of taxes) impairment charge on its 50 percent equity interest in Pilesgrove Solar, LLC (Pilesgrove), which owns an 18 MW (AC) solar electric production project in New Jersey. In August 2016, Con Edison Development acquired the remaining 50 percent equity interest in Pilesgrove for a purchase price of approximately $16 million and recorded a bargain purchase gain of $8 million ( $5 million , net of taxes); $45 million was recorded as non-utility property and the remaining $3 million was recorded as current assets. The impairment charge and bargain purchase gain are included in Investment and other income on Con Edison’s consolidated income statement. At December 31, 2018 and 2017 , net assets of the project were approximately $45 million . Con Edison's equity interest in Pilesgrove is consolidated in the financial statements. Sempra Solar On December 13, 2018, a Con Edison Development subsidiary completed its acquisition of Sempra Solar Holdings, LLC, a Sempra Energy subsidiary, for $ 1,609 million, including working capital and other closing adjustments of $69 million . Under the accounting rules for acquisitions, Con Edison has one year to finalize the purchase price allocation, including working capital adjustments and other closing adjustments. The acquired company has ownership interests in 981 megawatts (AC) of operating renewable electric production projects, including its 379 megawatts (AC) share of projects in which its subsidiaries had a 50 percent ownership interest (Acquired JV Interests) and other Con Edison Development subsidiaries had the remaining ownership interests (Previously-Owned JV Interests), and certain development rights with respect to solar electric production and energy storage projects. At the acquisition date, the acquired company’s subsidiaries had $1,454 million of tangible assets consisting mostly of property, plant and equipment, $878 million of intangible assets mostly arising from power purchase agreements, $4 million of other noncurrent assets, $568 million of project debt (including, in each case, amounts associated with the Acquired JV Interests) and $128 million of asset retirement obligation liabilities. The weighted average amortization period for these intangible assets is 16 years . At the acquisition date, the fair value of the noncontrolling interest attributable to the tax equity investors (see below) was $100 million . The acquisition date valuation was performed using a discounted cash flow approach . The fair values of assets acquired and liabilities assumed were determined based on significant estimates and assumptions that are judgmental in nature, including projected amounts and timing of future cash flows, discount rates reflecting risk inherent in the future cash flows and future power prices. Upon completion of the acquisition, the acquisition date fair value of the Previously-Owned JV Interests increased from $437 million to $568 million and Con Edison recognized a pre-tax gain of $131 million ( $89 million or $0.28 per share net of taxes). Prior to the acquisition, Con Edison had been accounting for the Previously-Owned JV Interests under the equity method. See "Investments" in Note A. Upon completion of the acquisition, Con Edison is accounting for Acquired JV Interests and the Previously-Owned JV Interests on a consolidated basis. Certain projects acquired have tax equity investors to which a percentage of earnings, tax attributes and cash flows are allocated. See Note Q. Con Edison has determined that the use of HLBV accounting is reasonable and appropriate to attribute income and loss to the tax equity investors. Using the HLBV method, the company's earnings from the projects are adjusted to reflect the income or loss allocable to the tax equity investors calculated based on how the project would allocate and distribute its cash if it were to sell all of its assets for their carrying amounts and liquidate at a particular point in time. Under the HLBV method, the company calculates the liquidation value allocable to the tax equity investors at the beginning and end of each period based on the contractual liquidation waterfall and adjusts its income for the period to reflect the change in the liquidation value allocable to the tax equity investors. Con Edison's revenues and net income for the years ended December 31, 2018 and 2017 as reported and pro forma to account on a consolidated basis for the acquisition as if the acquisition had been completed on January 1, 2017 instead of December 13, 2018 are as follows: Years ended December 31, (Millions of Dollars) 2018 2017 As Reported Revenue $12,337 $12,033 Net income 1,382 1,525 PRO FORMA SUPPLEMENTAL INFORMATION If Acquired January 1, 2017 (a)(b) Revenue $12,655 $12,331 Net income 1,279 1,612 (a) Reflects the following material adjustments: • included additional interest expense of $37 million and $38 million in 2018 and 2017, respectively, that would have been incurred if $825 million that was borrowed in December 2018 under a variable rate term loan agreement to fund a portion of the purchase price for the acquisition had instead been borrowed for such purpose on January 1, 2017 at a fixed rate of 4.64% per annum; and • with respect to the Previously-Owned JV Interests: eliminated the $131 million purchase accounting gain (pre-tax) that Con Edison recognized upon the completion of the acquisition in 2018 and reflected the $131 million purchase accounting gain in 2017; recorded the corresponding increase to the book value of the related net utility plant and power purchase agreement intangible asset as of January 1, 2017 instead of December 13, 2018, and included the increased depreciation and amortization expense in 2018 and 2017; and eliminated $33 million and $32 million of other income that Con Edison had recorded in 2018 and 2017, respectively, under the equity method of accounting. (b) Recalculating each investor’s claim on the investee’s assets under the contractual liquidation waterfall as if the acquisition had been completed on January 1, 2017 is impracticable. Accordingly, no HLBV adjustments were made. Dispositions Con Edison Solutions' Retail Electric Supply Business In July 2016, Con Edison Solutions entered into an agreement to sell the assets of its retail electric supply business (including retail contracts, related derivative instruments, information systems, and accounts receivable) to a subsidiary of Exelon Corporation (Exelon). In September 2016, the sale was completed for cash consideration of $235 million , subject to working capital adjustments. The sale resulted in a gain of $104 million ( $56 million , net of taxes), inclusive of a $65 million ( $42 million , net of taxes) gain on derivative instruments. The tax effect of the sale included $16 million ( $10 million , net of federal tax) of state taxes related to a change in the apportionment of state income taxes. Con Edison Solutions provided transition services to the Exelon subsidiary for operations and customer support through January 2018 during a portion of which period certain guarantees or other credit support provided by Con Edison in connection with the retail electric supply business continued in effect. Upton 2 In May 2017, Con Edison Development sold Upton 2, a development stage solar electric production project, for $11 million to Vistra Asset Co. and recorded a $1 million gain on sale ( $0.7 million , net of taxes). In addition, Con Edison Development agreed to perform the engineering, procurement and construction for the 180 MW (AC) project, which was substantially completed in the third quarter of 2018.

Schedule I - Condensed Financia

Schedule I - Condensed Financial Information	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Schedule I - Condensed Financial Information	Schedule I Condensed Financial Information of Consolidated Edison, Inc. (a) Condensed Statement of Income and Comprehensive Income (Parent Company Only) For the Years Ended December 31, (Millions of Dollars, except per share amounts) 2018 2017 2016 Equity in earnings of subsidiaries $1,447 $1,544 $1,254 Other income (deductions), net of taxes (6) 31 32 Interest expense (59) (50) (41) Net Income $1,382 $1,525 $1,245 Comprehensive Income $1,392 $1,526 $1,252 Net Income Per Share – Basic $4.43 $4.97 $4.15 Net Income Per Share – Diluted $4.42 $4.94 $4.12 Dividends Declared Per Share $2.86 $2.76 $2.68 Average Number Of Shares Outstanding—Basic (In Millions) 311.7 307.1 300.4 Average Number Of Shares Outstanding—Diluted (In Millions) 312.9 308.8 301.9 (a) These financial statements, in which Con Edison’s subsidiaries have been included using the equity method, should be read together with its consolidated financial statements and the notes thereto appearing above. Condensed Financial Information of Consolidated Edison, Inc. (a) Condensed Statement of Cash Flows (Parent Company Only) For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Net Income 1,382 1,525 1,245 Equity in earnings of subsidiaries (1,447) (1,544) (1,254) Dividends received from: CECONY 846 796 744 O&R 46 44 43 Clean Energy Businesses 15 12 10 Con Edison Transmission 10 8 — Change in Assets: Special deposits (8) — — Income taxes receivable 2 34 87 Other – net 187 21 (152) Net Cash Flows from Operating Activities 1,033 896 723 Investing Activities Contributions to subsidiaries (1,110) (434) (691) Debt receivable from affiliated companies (825) — (900) Net Cash Flows Used in Investing Activities (1,935) (434) (1,591) Financing Activities Net proceeds of short-term debt 164 (53) (53) Issuance of long-term debt 825 400 900 Retirement of long-term debt (3) (402) (2) Debt issuance costs — (2) (5) Issuance of common shares for stock plans, net of repurchases 53 51 51 Issuance of common shares - public offering 705 343 702 Common stock dividends (842) (803) (763) Net Cash Flows Used in Financing Activities 902 (466) 830 Net Change for the Period — (4) (38) Balance at Beginning of Period 9 13 51 Balance at End of Period $9 $9 $13 (a) These financial statements, in which Con Edison’s subsidiaries have been included using the equity method, should be read together with its consolidated financial statements and the notes thereto appearing above. Condensed Financial Information of Consolidated Edison, Inc. (a) Condensed Balance Sheet (Parent Company Only) December 31, (Millions of Dollars) 2018 2017 Assets Current Assets Cash and temporary cash investments $9 $9 Income taxes receivable 43 45 Term loan receivable from affiliated companies 825 — Accounts receivable from affiliated companies 536 687 Prepayments 33 36 Other current assets 12 18 Total Current Assets 1,458 795 Investments in subsidiaries 16,707 15,110 Goodwill 406 406 Deferred income tax 69 18 Long-term debt receivable from affiliated companies 900 900 Other noncurrent assets 2 2 Total Assets $19,542 $17,231 Liabilities and Shareholders’ Equity Current Liabilities Long-term debt due within one year $3 $2 Term loan 825 — Notes payable 495 331 Accounts payable 9 — Accounts payable to affiliated companies 274 274 Accrued taxes 2 — Other current liabilities 13 10 Total Current Liabilities 1,621 617 Total Liabilities 1,621 617 Long-term debt 1,195 1,195 Shareholders’ Equity Common stock, including additional paid-in capital 7,151 6,331 Retained earnings 9,575 9,088 Total Shareholders’ Equity 16,726 15,419 Total Liabilities and Shareholders’ Equity $19,542 $17,231 (a) These financial statements, in which Con Edison’s subsidiaries have been included using the equity method, should be read together with its consolidated financial statements and the notes thereto appearing above.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts For the Years Ended December 31, 2018 , 2017 and 2016 COLUMN C Additions Company (Millions of Dollars) COLUMN A Description COLUMN B Balance at Beginning of Period (1) Charged To Costs And Expenses (2) Charged To Other Accounts COLUMN D Deductions (b) COLUMN E Balance At End of Period Con Edison Allowance for uncollectible accounts (a): 2018 $70 $62 $— $64 $68 2017 $83 $64 $— $77 $70 2016 $96 $63 $— $76 $83 CECONY Allowance for uncollectible accounts (a): 2018 $65 $56 $— $60 $61 2017 $78 $60 $— $73 $65 2016 $91 $57 $— $70 $78 (a) This is a valuation account deducted in the balance sheet from the assets (Accounts receivable - customers and Other receivables) to which they apply. (b) Accounts written off less cash collections, miscellaneous adjustments and amounts reinstated as receivables previously written off.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Other Matters (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The Companies’ consolidated financial statements include the accounts of their respective majority-owned subsidiaries, and variable interest entities (see Note Q), as required. All intercompany balances and intercompany transactions have been eliminated.
Accounting Policies	Accounting Policies The accounting policies of Con Edison and its subsidiaries conform to generally accepted accounting principles in the United States of America (GAAP). For the Utilities, these accounting principles include the accounting rules for regulated operations and the accounting requirements of the Federal Energy Regulatory Commission (FERC) and the state regulators having jurisdiction. The accounting rules for regulated operations specify the economic effects that result from the causal relationship of costs and revenues in the rate-regulated environment and how these effects are to be accounted for by a regulated enterprise. Revenues intended to cover some costs may be recorded either before or after the costs are incurred. If regulation provides assurance that incurred costs will be recovered in the future, these costs would be recorded as deferred charges or “regulatory assets” under the accounting rules for regulated operations. If revenues are recorded for costs that are expected to be incurred in the future, these revenues would be recorded as deferred credits or “regulatory liabilities” under the accounting rules for regulated operations. The Utilities’ principal regulatory assets and liabilities are detailed in Note B. The Utilities are receiving or being credited with a return on all of their regulatory assets for which a cash outflow has been made, and are paying or being charged with a return on all of their regulatory liabilities for which a cash inflow has been received. The Utilities’ regulatory assets and liabilities will be recovered from customers, or applied for customer benefit, in accordance with rate provisions approved by the applicable state regulators.
Revenues	Revenues Adoption of New Standard On January 1, 2018, the Companies adopted Accounting Standards Codification (ASC) Topic 606, “Revenue from Contracts with Customers,” using the modified retrospective method applied to those contracts that were not completed. No charge to retained earnings for cumulative impact was required as a result of the Companies’ adoption of Topic 606. Revenue Recognition The following table presents, for the year ended December 31, 2018 , revenue from contracts with customers as defined in Topic 606, as well as additional revenue from sources other than contracts with customers, disaggregated by major source. (Millions of Dollars) Revenues from contracts with customers Other revenues (a) Total operating revenues CECONY Electric $7,920 $51 $7,971 Gas 2,052 26 2,078 Steam 625 6 631 Total CECONY $10,597 $83 $10,680 O&R Electric 647 (5) 642 Gas 256 (7) 249 Total O&R $903 $(12) $891 Clean Energy Businesses Renewables 329 (b) — 329 Energy services 95 — 95 Other — 339 339 Total Clean Energy Businesses $424 $339 $763 Con Edison Transmission 4 — 4 Other (c) — (1 ) (1 ) Total Con Edison $11,928 $409 $12,337 (a) For the Utilities, this includes revenue from alternative revenue programs, such as the revenue decoupling mechanisms under their New York electric and gas rate plans. For the Clean Energy Businesses, this includes revenue from wholesale services. (b) Included within the total for Renewables revenue at the Clean Energy Businesses is $103 million of revenue related to engineering, procurement and construction services. (c) Parent company and consolidation adjustments. Revenues are recorded as energy is delivered, generated or services are provided and billed to customers, except for services under percentage-of-completion contracts. Amounts billed are recorded in accounts receivable - customers, with payment generally due the following month. Con Edison’s and the Utilities’ accounts receivable - customers balance also reflects the Utilities’ purchase of receivables from energy service companies to support retail choice programs. Accrued revenues not yet billed to customers are recorded as accrued unbilled revenues. The Utilities have the obligation to deliver electricity, gas and steam energy to their customers. As the energy is immediately available for use upon delivery to the customer, the energy and its delivery are identifiable as a single performance obligation. The Utilities recognize revenues as this performance obligation is satisfied over time as the Utilities deliver, and the customers simultaneously receive and consume, the energy. The amount of revenues recognized reflects the consideration the Utilities expect to receive in exchange for delivering the energy. Under their tariffs, the transaction price for full-service customers includes the Utilities’ energy cost and for all customers includes delivery charges determined based on customer class and in accordance with established tariffs and guidelines of the New York State Public Service Commission (NYSPSC) or the New Jersey Board of Public Utilities (NJBPU), as applicable. Accordingly, there is no unsatisfied performance obligation associated with these customers. The transaction price is applied to the Utilities’ revenue generating activities through the customer billing process. Because energy is delivered over time, the Utilities use output methods that recognize revenue based on direct measurement of the value transferred, such as units delivered, which provides an accurate measure of value for the energy delivered. The Utilities accrue revenues at the end of each month for estimated energy delivered but not yet billed to customers. The Utilities defer over a 12 -month period net interruptible gas revenues, other than those authorized by the NYSPSC to be retained by the Utilities, for refund to firm gas sales and transportation customers. Con Edison Development recognizes revenue for the sale of energy from renewable electric production projects as energy is generated and billed to counterparties. Con Edison Development accrues revenues at the end of each month for energy generated but not yet billed to counterparties. Con Edison Energy recognizes revenue as energy is delivered and services are provided for managing energy supply assets leased from others and managing the dispatch, fuel requirements and risk management activities for generating plants and merchant transmission in the northeastern United States. Con Edison Solutions recognizes revenue for providing energy-efficiency services to government and commercial customers, and Con Edison Development recognizes revenue for engineering, procurement and construction services, under the percentage-of-completion method of revenue recognition. Sales and profits on each percentage-of-completion contract are recorded each month based on the ratio of actual cumulative costs incurred to the total estimated costs at completion of the contract, multiplied by the total estimated contract revenue, less cumulative revenues recognized in prior periods (the ‘‘cost-to-cost’’ method). The impact of revisions of contract estimates, which may result from contract modifications, performance or other reasons, are recognized on a cumulative catch-up basis in the period in which the revisions are made. (Millions of Dollars) Unbilled contract revenue (a) Unearned revenue (b) Beginning balance as of January 1, 2018 $58 $87 Additions (c) 144 38 Subtractions (c) 173 105 (d) Ending balance as of December 31, 2018 $29 $20 (a) Unbilled contract revenue represents accumulated incurred costs and earned profits on contracts (revenue arrangements), which have been recorded as revenue, but have not yet been billed to customers, and which represent contract assets as defined in Topic 606. Substantially all accrued unbilled contract revenue is expected to be collected within one year. Unbilled contract revenue arises from the cost-to-cost method of revenue recognition. Unbilled contract revenue from fixed-price type contracts is converted to billed receivables when amounts are invoiced to customers according to contractual billing terms, which generally occur when deliveries or other performance milestones are completed. (b) Unearned revenue represents a liability for billings to customers in excess of earned revenue, which are contract liabilities as defined in Topic 606. (c) Additions for unbilled contract revenue and subtractions for unearned revenue represent additional revenue earned. Additions for unearned revenue and subtractions for unbilled contract revenue represent billings. Activity also includes appropriate balance sheet classification for the period. (d) Of the $105 million in subtractions from unearned revenue, $50 million was included in the balance as of December 31, 2017. As of December 31, 2018 , the aggregate amount of the remaining fixed performance obligations is $95 million , of which $59 million will be recognized within the next two years, and the remaining $36 million will be recognized pursuant to long-term service and maintenance agreements. CECONY’s electric and gas rate plans and O&R’s New York electric and gas rate plans each contain a revenue decoupling mechanism under which the company’s actual energy delivery revenues are compared with the authorized delivery revenues and the difference accrued, with interest, for refund to, or recovery from, customers, as applicable. See “Rate Plans” in Note B. The NYSPSC requires utilities to record gross receipts tax revenues and expenses on a gross income statement presentation basis (i.e., included in both revenue and expense). The recovery of these taxes is generally provided for in the revenue requirement within each of the respective NYSPSC approved rate plans.
Plant and Depreciation	Non–Utility Plant Non-utility plant is stated at original cost. For Con Edison, non-utility plant consists primarily of the Clean Energy Businesses’ renewable electric production and gas storage. For the Utilities, non-utility plant consists of land and conduit for telecommunication use. Depreciation on these assets is computed using the straight-line method for financial statement purposes over their estimated useful lives, which range from 3 to 30 years . Plant and Depreciation Utility Plant Utility plant is stated at original cost. The cost of repairs and maintenance is charged to expense and the cost of betterments is capitalized. The capitalized cost of additions to utility plant includes indirect costs such as engineering, supervision, payroll taxes, pensions, other benefits and an allowance for funds used during construction (AFUDC). The original cost of property is charged to expense over the estimated useful lives of the assets. Upon retirement, the original cost of property is charged to accumulated depreciation. See Note R. Rates used for AFUDC include the cost of borrowed funds and a reasonable rate of return on the Utilities’ own funds when so used, determined in accordance with regulations of the FERC or the state public utility regulatory authority having jurisdiction. The rate is compounded semiannually, and the amounts applicable to borrowed funds are treated as a reduction of interest charges, while the amounts applicable to the Utilities’ own funds are credited to other income (deductions). The AFUDC rates for CECONY were 5.4 percent , 5.5 percent and 4.7 percent for 2018 , 2017 and 2016 , respectively. The AFUDC rates for O&R were 2.2 percent , 2.5 percent and 3.5 percent for 2018 , 2017 and 2016 , respectively. The Utilities generally compute annual charges for depreciation using the straight-line method for financial statement purposes, with rates based on average service lives and net salvage factors. The average depreciation rates for CECONY were 3.1 percent for 2018 , 2017 and 2016 . The average depreciation rates for O&R were 2.9 percent for 2018 , 2017 and 2016 . The estimated lives for utility plant for CECONY range from 5 to 95 years for electric, 5 to 100 years for gas, 5 to 80 years for steam and 5 to 55 years for general plant. For O&R, the estimated lives for utility plant range from 5 to 75 years for electric and gas and 5 to 50 years for general plant.
Goodwill	Goodwill Con Edison tests goodwill for impairment at least annually or whenever there is a triggering event. There is an option to first make a qualitative assessment of whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount before applying a two-step, quantitative goodwill impairment test. Con Edison has elected to perform the qualitative assessment for substantially all of its goodwill and, if needed, applies the two-step quantitative approach. The first step of the quantitative goodwill impairment test compares the estimated fair value of a reporting unit with its carrying value, including goodwill. If the estimated fair value of a reporting unit exceeds its carrying value, goodwill of the reporting unit is considered not impaired. If the carrying value exceeds the estimated fair value of the reporting unit, the second step is performed to measure the amount of impairment loss, if any. The second step requires a calculation of the implied fair value of goodwill.
Long-Lived and Intangible Assets	Long–Lived and Intangible Assets Con Edison evaluates the impairment of long-lived assets and intangible assets with definite lives, based on projections of undiscounted future cash flows, which projections may vary significantly from future projections or actual cash flows, whenever events or changes in circumstances indicate that the carrying amounts of such assets may not be recoverable. In the event an evaluation indicates that such cash flows cannot be expected to be sufficient to fully recover the assets, the assets are written down to their estimated fair value.
Recoverable Energy Costs/New York Independent System Operator (NYISO)	Recoverable Energy Costs The Utilities generally recover all of their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state public utility regulators. If the actual energy supply costs for a given month are more or less than the amounts billed to customers for that month, the difference in most cases is recoverable from or refundable to customers. Differences between actual and billed electric and steam supply costs and costs of its electric demand management programs are generally deferred for charge or refund to customers during the next billing cycle (normally within one or two months ). For the Utilities’ gas costs, differences between actual and billed gas costs during the 12-month period ending each August are charged or refunded to customers during a subsequent 12-month period. New York Independent System Operator (NYISO) The Utilities purchase electricity through the wholesale electricity market administered by the NYISO. The difference between purchased power and related costs initially billed to the Utilities by the NYISO and the actual cost of power subsequently calculated by the NYISO is refunded by the NYISO to the Utilities, or paid to the NYISO by the Utilities. The reconciliation payments or receipts are recoverable from or refundable to the Utilities’ customers. Certain other payments to or receipts from the NYISO are also subject to reconciliation, with shortfalls or amounts in excess of specified rate allowances recoverable from or refundable to customers. These include proceeds from the sale through the NYISO of transmission rights on CECONY’s transmission system (transmission congestion contracts or TCCs).
Temporary Cash Investments	Temporary Cash Investments Temporary cash investments are short-term, highly-liquid investments that generally have maturities of three months or less at the date of purchase. They are stated at cost, which approximates market. The Companies consider temporary cash investments to be cash equivalents.
Investments	Investments Investments consist primarily of the investments of Con Edison Transmission and the Clean Energy Businesses that are accounted for under the equity method, and the fair value of the Utilities’ supplemental retirement income plan and deferred income plan assets.
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits The accounting rules for retirement benefits require an employer to recognize an asset or liability for the overfunded or underfunded status of its pension and other postretirement benefit plans. For a pension plan, the asset or liability is the difference between the fair value of the plan’s assets and the projected benefit obligation. For any other postretirement benefit plan, the asset or liability is the difference between the fair value of the plan’s assets and the accumulated postretirement benefit obligation. The accounting rules generally require employers to recognize all unrecognized prior service costs and credits and unrecognized actuarial gains and losses in accumulated other comprehensive income/(loss) (OCI), net of tax. Such amounts will be adjusted as they are subsequently recognized as components of total periodic benefit cost or income pursuant to the current recognition and amortization provisions. For the Utilities’ pension and other postretirement benefit plans, regulatory accounting treatment is generally applied in accordance with the accounting rules for regulated operations. Unrecognized prior service costs or credits and unrecognized actuarial gains and losses are recorded to regulatory assets or liabilities, rather than OCI. See Notes E and F. The total periodic benefit costs are recognized in accordance with the accounting rules for retirement benefits. Investment gains and losses are recognized in expense over a 15 -year period and other actuarial gains and losses are recognized in expense over a 10 -year period, subject to the deferral provisions in the rate plans. In accordance with the Statement of Policy issued by the NYSPSC and its current electric, gas and steam rate plans, CECONY defers for payment to or recovery from customers the difference between such expenses and the amounts for such expenses reflected in rates. Generally, O&R also defers such difference pursuant to its rate plans. See Note B. The Companies calculate the expected return on pension and other postretirement benefit plan assets by multiplying the expected rate of return on plan assets by the market-related value (MRV) of plan assets at the beginning of the year, taking into consideration anticipated contributions and benefit payments that are to be made during the year. The accounting rules allow the MRV of plan assets to be either fair value or a calculated value that recognizes changes in fair value in a systematic and rational manner over not more than five years. The Companies use a calculated value when determining the MRV of the plan assets that adjusts for 20 percent of the difference between fair value and expected MRV of plan assets. This calculated value has the effect of stabilizing variability in assets to which the Companies apply the expected return.
Federal Income Tax/State Income Tax	Federal Income Tax In accordance with accounting rules for income taxes, the Companies have recorded an accumulated deferred federal income tax liability at current tax rates for temporary differences between the book and tax basis of assets and liabilities. In accordance with rate plans, the Utilities have recovered amounts from customers for a portion of the tax liability they will pay in the future as a result of the reversal or “turn-around” of these temporary differences. As to the remaining deferred tax liability, the Utilities had established regulatory assets for the net revenue requirements to be recovered from customers for the related future tax expense pursuant to the NYSPSC's 1993 Policy Statement approving accounting procedures consistent with accounting rules for income taxes and providing assurances that these future increases in taxes will be recoverable in rates. Upon enactment of the Tax Cuts and Jobs Act of 2017 on December 22, 2017 (the TCJA), the Companies re-measured their deferred tax assets and liabilities based upon the 21 percent corporate income tax rate under the TCJA. See “Other Regulatory Matters” and “Regulatory Assets and Liabilities” in Note B and Note L. Accumulated deferred investment tax credits are amortized ratably over the lives of the related properties and applied as a reduction to future federal income tax expense. Con Edison and its subsidiaries file a consolidated federal income tax return. The consolidated income tax liability is allocated to each member of the consolidated group using the separate return method. Each member pays or receives an amount based on its own taxable income or loss in accordance with a consolidated tax allocation agreement. Tax loss and tax credit carryforwards are allocated among members in accordance with consolidated tax return regulations. State Income Tax Con Edison and its subsidiaries file a combined New York State Corporation Business Franchise Tax Return. Similar to a federal consolidated income tax return, the income of all entities in the combined group is subject to New York State taxation, after adjustments for differences between federal and New York law and apportionment of income among the states in which the company does business. Each member’s share of the New York State tax is based on its own New York State taxable income or loss.
Research and Development Costs	Research and Development Costs Research and development costs are charged to operating expenses as incurred.
Reclassification	Reclassification Certain prior year amounts have been reclassified to conform with the current year presentation.
Earnings Per Common Share	Earnings Per Common Share Con Edison presents basic and diluted earnings per share on the face of its consolidated income statement. Basic earnings per share (EPS) are calculated by dividing earnings available to common shareholders (“Net income” on Con Edison’s consolidated income statement) by the weighted average number of Con Edison common shares outstanding during the period. In the calculation of diluted EPS, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for Con Edison consist of restricted stock units and deferred stock units for which the average market price of the common shares for the period was greater than the exercise price (see Note M) and its common shares that are subject to certain forward sale agreements (see Note C). Before the issuance of common shares upon settlement of the forward sale agreements, the shares will be reflected in the company’s diluted earnings per share calculations using the treasury stock method. Under this method, the number of common shares used in calculating diluted earnings per share is deemed to be increased by the excess, if any, of the number of shares that would be issued upon physical settlement of the forward sale agreements over the number of shares that could be purchased by the company in the market (based on the average market price during the period) using the proceeds due upon physical settlement (based on the adjusted forward sale price at the end of the reporting period).
Estimates	Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
New Financial Accounting Standards	New Financial Accounting Standards In January 2019, the Companies adopted Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842),” including the amendments thereto (the New Standard), using a modified retrospective transition method of adoption. The New Standard supersedes the lease requirements within Accounting Standard Codification (ASC) Topic 840, “Leases.” The New Standard requires lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Under the New Standard, lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The Utilities, as regulated entities, are permitted to continue to recognize expense using the timing that conforms to the regulatory rate treatment. Lessor accounting is similar to the previous model, but updated to align with “Revenue from Contracts with Customers (Topic 606)." Upon adoption of the New Standard, the Companies elected the following practical expedients: (1) for leases commenced prior to adoption date, the following three transition expedients that will allow the Companies to not reassess: (a) whether expired contracts contain leases; (b) the lease classification for expired leases and (c) the initial direct costs for existing leases; (2) for an underlying asset class, an expedient that allows the Companies to not apply the recognition requirements to short-term leases and an expedient that will allow the Companies to account for lease and associated non-lease components as a single lease component; (3) an expedient that allows the use of hindsight to determine lease term; and (4) an expedient that allows the Companies to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. For leases previously classified as operating leases, upon adoption of the New Standard, the Companies recognized on their balance sheets right-of-use assets and corresponding lease liabilities of approximately $875 million and $635 million for Con Edison and CECONY, respectively, as of January 1, 2019. The adoption of the New Standard will not have a material effect on the Companies’ liquidity or results of operations. The Companies will prepare additional disclosures as required by the New Standard beginning in 2019. The Companies implemented additional internal controls related to the New Standard, however the adoption of the New Standard is not expected to require a change that will materially affect the Companies’ internal control over financial reporting. In January 2017, the FASB issued amendments to the guidance for the subsequent measurement of goodwill through ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The amendments in this update simplify goodwill impairment testing by eliminating Step 2 of the goodwill impairment test wherein an entity has to compute the implied fair value of goodwill by performing procedures to determine the fair value of its assets and liabilities. Under the new guidance, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value up to the total amount of goodwill allocated to that reporting unit. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2017, the FASB issued amendments to the guidance for debt securities through ASU 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” The amendments in this update shorten the amortization period for certain callable debt securities held at a premium. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The application of this guidance will not have a material impact on the Companies’ financial position, results of operations and liquidity. In August 2017, the FASB issued amendments to the guidance for derivatives and hedging through ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this update provide greater clarification on hedge accounting for risk components, presentation and disclosure of hedging instruments, and overall targeted improvements to simplify hedge accounting. For public entities, the amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The application of the guidance will not have a material impact on the Companies’ financial position, results of operations and liquidity. In February 2018, the FASB issued amendments to the guidance for reporting comprehensive income through ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The amendments allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the TCJA. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Companies adopted the amendments in the fourth quarter of 2018. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial. In August 2018, the FASB issued amendments to the guidance for internal use software through ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract.” The amendments align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Companies elected to adopt the amendments in the third quarter of 2018, prospectively for all in-scope implementation costs incurred after the date of adoption. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Other Matters (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Disaggregation of Revenue	The following table presents, for the year ended December 31, 2018 , revenue from contracts with customers as defined in Topic 606, as well as additional revenue from sources other than contracts with customers, disaggregated by major source. (Millions of Dollars) Revenues from contracts with customers Other revenues (a) Total operating revenues CECONY Electric $7,920 $51 $7,971 Gas 2,052 26 2,078 Steam 625 6 631 Total CECONY $10,597 $83 $10,680 O&R Electric 647 (5) 642 Gas 256 (7) 249 Total O&R $903 $(12) $891 Clean Energy Businesses Renewables 329 (b) — 329 Energy services 95 — 95 Other — 339 339 Total Clean Energy Businesses $424 $339 $763 Con Edison Transmission 4 — 4 Other (c) — (1 ) (1 ) Total Con Edison $11,928 $409 $12,337 (a) For the Utilities, this includes revenue from alternative revenue programs, such as the revenue decoupling mechanisms under their New York electric and gas rate plans. For the Clean Energy Businesses, this includes revenue from wholesale services. (b) Included within the total for Renewables revenue at the Clean Energy Businesses is $103 million of revenue related to engineering, procurement and construction services. (c) Parent company and consolidation adjustments.
Change in Unbilled Contract and Unearned Revenues	(Millions of Dollars) Unbilled contract revenue (a) Unearned revenue (b) Beginning balance as of January 1, 2018 $58 $87 Additions (c) 144 38 Subtractions (c) 173 105 (d) Ending balance as of December 31, 2018 $29 $20 (a) Unbilled contract revenue represents accumulated incurred costs and earned profits on contracts (revenue arrangements), which have been recorded as revenue, but have not yet been billed to customers, and which represent contract assets as defined in Topic 606. Substantially all accrued unbilled contract revenue is expected to be collected within one year. Unbilled contract revenue arises from the cost-to-cost method of revenue recognition. Unbilled contract revenue from fixed-price type contracts is converted to billed receivables when amounts are invoiced to customers according to contractual billing terms, which generally occur when deliveries or other performance milestones are completed. (b) Unearned revenue represents a liability for billings to customers in excess of earned revenue, which are contract liabilities as defined in Topic 606. (c) Additions for unbilled contract revenue and subtractions for unearned revenue represent additional revenue earned. Additions for unearned revenue and subtractions for unbilled contract revenue represent billings. Activity also includes appropriate balance sheet classification for the period. (d) Of the $105 million in subtractions from unearned revenue, $50 million was included in the balance as of December 31, 2017.
Schedule of Total Excise Taxes Recorded in Operating Revenues	Total excise taxes (inclusive of gross receipts taxes) recorded in operating revenues were as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $330 $302 $336 CECONY 318 292 316
Capitalized Cost of Utility Plant	At December 31, 2018 and 2017 , the capitalized cost of the Companies’ utility plant, net of accumulated depreciation, was as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Electric Generation $593 $544 $592 $544 Transmission 3,333 3,210 3,106 2,990 Distribution 19,750 18,959 18,716 17,996 Gas (a) 7,714 6,976 7,107 6,403 Steam 1,830 1,798 1,830 1,798 General 2,306 2,105 2,102 1,905 Held for future use 76 76 67 67 Construction work in progress 1,978 1,605 1,850 1,502 Net Utility Plant $37,580 $35,273 $35,370 $33,205 (a) Primarily distribution.
Schedule of Investment Assets	The following investment assets are included in the Companies' consolidated balance sheets at December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 CET Gas investment in Stagecoach Gas Services, LLC $948 $971 $— $— CET Gas investment in Mountain Valley Pipeline, LLC (a) 363 98 — — Supplemental retirement income plan assets (c) 326 330 301 301 Deferred income plan assets 75 73 75 73 CET Electric investment in New York Transco, LLC 52 53 — — Con Edison Development equity method investments (b) — 467 — — Other 2 9 9 9 Total investments $1,766 $2,001 $385 $383 (a) See Note U. (b) Upon completion of the acquisition of Sempra Solar Holdings, LLC in December 2018, Con Edison is accounting on a consolidated basis for certain jointly-owned renewable electric production projects that previously were accounted for as equity method investments. See Note U. (c) See Note E.
Research and Development Costs	Research and development costs were as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $24 $24 $24 CECONY 23 23 22
Basic and Diluted EPS	Basic and diluted EPS for Con Edison are calculated as follows: For the Years Ended December 31, (Millions of Dollars, except per share amounts/Shares in Millions) 2018 2017 2016 Net income $1,382 $1,525 $1,245 Weighted average common shares outstanding – basic 311.7 307.1 300.4 Add: Incremental shares attributable to effect of potentially dilutive securities 1.2 1.7 1.5 Adjusted weighted average common shares outstanding – diluted 312.9 308.8 301.9 Net Income per common share – basic $4.43 $4.97 $4.15 Net Income per common share – diluted $4.42 $4.94 $4.12
Changes in Accumulated Other Comprehensive Income/(Loss)	Changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: (Millions of Dollars) Con Edison CECONY Accumulated OCI, net of taxes, at December 31, 2015 (a) $(34) $(9) OCI before reclassifications, net of tax of $(1) for Con Edison and CECONY 2 1 Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(3) and $(1) for Con Edison and CECONY, respectively (a)(b) 5 1 Total OCI, net of taxes, at December 31, 2016 7 2 Accumulated OCI, net of taxes, at December 31, 2016 (a) $(27) $(7) OCI before reclassifications, net of tax of $3 and $1 for Con Edison and CECONY, respectively (4) — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(3) and $(1) for Con Edison and CECONY, respectively (a)(b) 5 1 Total OCI, net of taxes, at December 31, 2017 1 1 Accumulated OCI, net of taxes, at December 31, 2017 (a) $(26) $(6) OCI before reclassifications, net of tax of $3 for Con Edison 4 — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(2) for Con Edison (a)(b) 6 1 Total OCI, net of taxes, at December 31, 2018 10 1 Accumulated OCI, net of taxes, at December 31, 2018 (a) $(16) $(5) (a) Tax reclassified from accumulated OCI is reported in the income tax expense line item of the consolidated income statement. (b) For the portion of unrecognized pension and other postretirement benefit costs relating to the Utilities, costs are recorded into, and amortized out of, regulatory assets and liabilities instead of OCI. The net actuarial losses and prior service costs recognized during the period are included in the computation of total periodic pension and other postretirement benefit cost. See Notes E and F.
Restrictions on Cash and Cash Equivalents	At December 31, 2018 and 2017 , cash, temporary cash investments and restricted cash for Con Edison and CECONY were as follows: At December 31, Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Cash and temporary cash investments $895 $797 $818 $730 Restricted cash (a) 111 47 — — Total cash, temporary cash investments and restricted cash $1,006 $844 $818 $730 (a) Restricted cash included cash of Con Edison Development renewable electric production project subsidiaries ( $109 million and $46 million at December 31, 2018 and 2017 , respectively) that, under the related project debt agreements, is restricted until the various maturity dates of the project debt to being used for normal operating expenses and capital expenditures, debt service, and required reserves. Also, during the pendency of the PG&E bankruptcy, restricted cash may also include additional cash that, unless the lenders for the related project debt agree, may not be distributed from the related projects to Con Edison Development. See "Long-Lived and Intangible Assets,” above. In addition, restricted cash includes O&R's New Jersey utility subsidiary, Rockland Electric Company transition bond charge collections, net of principal, interest, trustee and service fees ( $2 million and $1 million at December 31, 2018 and 2017 , respectively) that are restricted until the bonds mature in 2019.
Schedule of Cash and Cash Equivalents	At December 31, 2018 and 2017 , cash, temporary cash investments and restricted cash for Con Edison and CECONY were as follows: At December 31, Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Cash and temporary cash investments $895 $797 $818 $730 Restricted cash (a) 111 47 — — Total cash, temporary cash investments and restricted cash $1,006 $844 $818 $730 (a) Restricted cash included cash of Con Edison Development renewable electric production project subsidiaries ( $109 million and $46 million at December 31, 2018 and 2017 , respectively) that, under the related project debt agreements, is restricted until the various maturity dates of the project debt to being used for normal operating expenses and capital expenditures, debt service, and required reserves. Also, during the pendency of the PG&E bankruptcy, restricted cash may also include additional cash that, unless the lenders for the related project debt agree, may not be distributed from the related projects to Con Edison Development. See "Long-Lived and Intangible Assets,” above. In addition, restricted cash includes O&R's New Jersey utility subsidiary, Rockland Electric Company transition bond charge collections, net of principal, interest, trustee and service fees ( $2 million and $1 million at December 31, 2018 and 2017 , respectively) that are restricted until the bonds mature in 2019.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2018
Regulated Operations [Abstract]
Summary of Utilities Rate Plans	The following tables contain a summary of the Utilities’ rate plans: CECONY – Electric Effective period January 2014 – December 2016 January 2017 – December 2019 (b) Base rate changes Yr. 1 – $(76.2) million (a) Yr. 1 – $195 million (c) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 and 2 – $(37) million (d) Yr. 1 – $84 million Other revenue sources Retention of $90 million of annual transmission congestion revenues. Retention of $75 million of annual transmission congestion revenues. In 2017 and 2018, the company recorded $13 million and $25 million of earnings adjustment mechanism incentives for energy efficiency, respectively. The company also achieved other incentives of $5 million in 2017 and 2018 that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $3 million for service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred for customer benefit $146 million, $98 million and $101 million of revenues, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs (e) Current rate recovery of purchased power and fuel costs. Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $400 million annually) if certain performance targets are not met. In 2014, the company recorded a $5 million negative revenue adjustment. In 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $57 million, $26 million and $68 million of net regulatory liabilities, respectively (f). Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes (f), municipal infrastructure support costs (g), the impact of new laws and environmental site investigation and remediation to amounts reflected in rates (h). Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $17,323 million Yr. 1 – $18,902 million Weighted average cost of capital (after-tax) Yr. 1 – 7.05 percent Yr. 1 – 6.82 percent Authorized return on common equity Yrs. 1 and 2 – 9.2 percent 9.0 percent Actual return on common equity Yr. 1 – 9.04 percent Yr. 1 – 9.30 percent Earnings sharing Most earnings above an annual earnings threshold of 9.8 percent for Yrs. 1 and 2 and 9.6 percent for Yr. 3 are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014 the company had no earnings above the threshold. Actual earnings were $44.4 million and $6.5 million above the threshold for 2015 and 2016, respectively. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred; this amount was amortized to $0 at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's electric rate plan for January 2017 through December 2019. If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , CECONY is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (c) The electric base rate increases are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. At the NYSPSC’s option, these increases are being implemented with increases of $199 million in each rate year. Base rates reflect recovery by the company of certain costs of its energy efficiency, system peak reduction and electric vehicle programs (Yr. 1 - $20.5 million ; Yr. 2 - $49 million ; and Yr. 3 - $107.5 million ) over a ten -year period, including the overall pre-tax rate of return on such costs. (d) Amounts reflect annual amortization of $107 million of the regulatory asset for deferred Superstorm Sandy and other major storm costs. The costs recoverable from customers were reduced by $4 million . The costs are no longer subject to NYSPSC staff review and the recovery of the costs is no longer subject to refund. In 2016, an additional $123 million of net regulatory liabilities were amortized to income. (e) For transmission service provided pursuant to the open access transmission tariff of PJM Interconnection LLC (PJM), unless and until changed by the NYSPSC, the company will recover all charges incurred associated with the transmission service. In April 2017, the transmission service terminated because CECONY did not exercise its option to continue the service. See "Other Regulatory Matters," below. (f) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points ( 5.0 , 7.5 or 10.0 basis points , depending on the year). (g) In general, if actual expenses for municipal infrastructure support (other than company labor) are below the amounts reflected in rates the company will defer the difference for credit to customers, and if the actual expenses are above the amount reflected in rates the company will defer for recovery from customers 80 percent of the difference subject to a maximum deferral of 30 percent of the amount reflected in rates. (h) In addition, amounts reflected in rates relating to the regulatory asset for future income tax and the excess deferred federal income tax liability are subject to reconciliation. The NYSPSC staff is to audit the regulatory asset and the tax liability. Differences resulting from the NYSPSC staff review will be deferred for NYSPSC determination of any amounts to be refunded or collected from customers. See "Other Regulatory Matters," below. In January 2019, CECONY filed a request with the NYSPSC for an electric rate increase of $485 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, storms, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 100 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism and the provisions pursuant to which the company recovers its purchased power and fuel costs from customers. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding electric rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $352 million and $263 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Gas Effective period January 2014 – December 2016 January 2017 - December 2019 (b) Base rate changes Yr. 1 – $(54.6) million (a) Yr. 1 – $(5) million (b) Amortizations to income of net regulatory (assets) and liabilities $4 million over three years Yr. 1 – $39 million Other revenue sources Retention of revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. The company retained $70 million, $66 million and $65 million of such revenues in 2014, 2015 and 2016, respectively. Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. In 2017 and 2018, the company achieved incentives of $7 million and $6 million, respectively that, pursuant to the rate plan, is being recorded ratably in earnings from 2018 to 2020. In 2018, the company recorded $5 million for gas leak backlog, leak prone pipe and service terminations. Revenue decoupling mechanisms In 2014, 2015 and 2016, the company deferred $28 million, $54 million and $71 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $33 million in 2014, $44 million in 2015, and $56 million in 2016) if certain gas performance targets are not met. In 2014, 2015 and 2016, the company did not record any negative revenue adjustments. Potential penalties if performance targets relating to service, safety and other matters are not met: Cost reconciliations In 2014, 2015 and 2016, the company deferred $38 million, $11 million, and $32 million of net regulatory liabilities, respectively. (c) Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes, municipal infrastructure support costs, the impact of new laws and environmental site investigation and remediation to amounts reflected in rates. (d) Net utility plant reconciliations Target levels reflected in rates were: Target levels reflected in rates: Average rate base Yr. 1 – $3,521 million Yr. 1 – $4,841 million Weighted average cost of capital Yr. 1 – 7.10 percent Yr. 1 – 6.82 percent Authorized return on common equity 9.3 percent 9.0 percent Actual return on common equity Yr. 1 – 8.02 percent Yr. 1 – 9.22 percent Earnings sharing Most earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. In 2014, 2015 and 2016, the company had no earnings above the threshold. Most earnings above an annual earnings threshold of 9.5 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.17 percent Yr. 1 – 4.93 percent Common equity ratio 48 percent 48 percent (a) The impact of these base rate changes was deferred which resulted in a $32 million regulatory liability at December 31, 2016. (b) In January 2017, the NYSPSC approved the September 2016 Joint Proposal for CECONY's gas rate plan for January 2017 through December 2019. The gas base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the prior rate plan. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity (d) See footnotes (e), (f), (g) and (h) to the table under "CECONY - Electric" above. In January 2019, CECONY filed a request with the NYSPSC for a gas rate increase of $210 million , effective January 2020. The filing reflects a return on common equity of 9.75 percent and a common equity ratio of 50 percent . The company is requesting provisions pursuant to which expenses for pension and other postretirement benefits, variable-rate debt, property taxes and municipal infrastructure support, the impact of new laws and environmental site investigation and remediation are reconciled to amounts reflected in rates. The company is also proposing full reconciliation of capital interference costs. In addition, the company is, among other things, proposing continuation of earnings opportunities from Earnings Adjustment Mechanisms (EAM) for meeting energy efficiency goals. The proposed EAM earnings opportunities are at 70 basis points of common equity annually. The filing also reflects continuation of the revenue decoupling mechanism (RDM) and provisions pursuant to which the company recovers its purchased gas costs from customers. Within the filing, the company is proposing to change the gas RDM from a revenue per customer methodology to a revenue per class methodology. The requested rate increase was mitigated, in part, by the TCJA, including reduced tax rate, and amortization of excess deferred income taxes and 2018 tax savings. See "Other Regulatory Matters," below. The filing includes supplemental information regarding gas rate plans for 2021 and 2022, which the company is not requesting but would consider through settlement discussions. For purposes of illustration, rate increases of $138 million and $155 million effective January 2021 and 2022, respectively, were calculated based upon an assumed return on common equity of 9.75 percent and a common equity ratio of 50 percent . CECONY – Steam Effective period January 2014 – December 2016 (a) Base rate changes Yr. 1 – $(22.4) million (b) Amortizations to income of net regulatory (assets) and liabilities $37 million over three years Recoverable energy costs Current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties (up to $1 million annually) if certain steam performance targets are not met. In 2014, 2015, 2016 and 2017 and 2018, the company did not record any negative revenue adjustments. Cost reconciliations (c) In 2014, 2015, 2016 2017 and 2018, the company deferred $42 million of net regulatory liabilities, $17 million of net regulatory assets, $8 million and $14 million of net regulatory liabilities, and $1 million of net regulatory assets, respectively. Net utility plant reconciliations Target levels reflected in rates were: Average rate base Yr. 1 – $1,511 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Authorized return on common equity 9.3 percent Actual return on common equity Yr. 1 – 9.82 percent Earnings sharing Weather normalized earnings above an annual earnings threshold of 9.9 percent are to be applied to reduce regulatory assets for environmental remediation and other costs. Cost of long-term debt Yr. 1 – 5.17 percent Common equity ratio 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) The impact of these base rate changes was deferred which resulted in an $8 million regulatory liability at December 31, 2016. (c) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a 10 basis point impact on return on common equity. In November 2018, O&R, the staff of the NYSPSC and other parties entered into a Joint Proposal for new electric and gas rate plans for the three-year period January 2019 through December 2021 (the Joint Proposal). The Joint Proposal is subject to NYSPSC approval. The following tables contain a summary of the current and proposed rate plans. O&R New York – Electric Effective period November 2015 - October 2017 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $9.3 million Yr. 1 – $13.4 million (e) Amortizations to income of net regulatory (assets) and liabilities Yr. 1 – $(8.5) million (b) Yr. 1 – $(1.5) million (f) Other revenue sources Potential earnings adjustment mechanism incentives for peak reduction, energy efficiency, Distributed Energy Resources utilization and other potential incentives of up to: Yr. 1 - $3.6 million; Yr. 2 - $4.0 million; and Yr. 3 - $4.2 million. Revenue decoupling mechanisms In 2015, 2016, 2017 and 2018, the company deferred for the customer’s benefit an immaterial amount, $6.3 million as regulatory liabilities, $11.2 million as regulatory asset and $0.5 million as regulatory asset, respectively. Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power costs. Continuation of current rate recovery of purchased power costs. Negative revenue adjustments Potential penalties (up to $4 million annually) if certain performance targets are not met. In 2015 the company recorded $1.25 million in negative revenue adjustments. In 2016, 2017 and 2018, the company did not record any negative revenue adjustments. Potential penalties if certain performance targets relating to service, reliability and other matters are not met: Yr. 1 - $4.4 million; Yr. 2 - $4.4 million; and Yr. 3 - $4.5 million. Cost reconciliations In 2015, 2016 and 2017, the company deferred $0.3 million, $7.4 million and $3.2 million as net decreases to regulatory assets, respectively. In 2018, the company deferred $5 million as a net regulatory asset. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), major storms, the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $763 million Yr. 1 – $878 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 10.8 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $6.1 million, $0.3 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates determined pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) $59.3 million of the regulatory asset for deferred storm costs is to be recovered from customers over a five year period, including $11.85 million in each of years 1 and 2, $1 million of the regulatory asset for such costs will not be recovered from customers, and all outstanding issues related to Superstorm Sandy and other past major storms prior to November 2014 are resolved. Approximately $4 million of regulatory assets for property tax and interest rate reconciliations will not be recovered from customers. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes electric AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $1 million in year 1 and $9 million in year 2. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with increases of: Yr. 1 - $8.6 million ; Yr. 2 - $12.1 million ; and Yr. 3 - $12.2 million . (f) Reflects amortization of, among other things, the Company’s net benefits under the TCJA prior to January 1, 2019, amortization of net regulatory liability for future income taxes and reduction of previously incurred regulatory assets for environmental remediation costs. Also, for electric, reflects amortization over a six year period of previously incurred incremental major storm costs. See "Other Regulatory Matters," below. (g) Deferrals for property taxes are limited to 90 percent of the difference from amounts reflected in rates, subject to an annual maximum for the remaining difference of not more than a maximum number of basis points impact on return on common equity: Yr. 1 - 10.0 basis points; Yr. 2 - 7.5 basis points; and Yr. 3 - 5.0 basis points. (h) Energy efficiency costs are expensed as incurred. Such costs are subject to a downward-only reconciliation over the terms of the electric and gas rate plans. The Company will defer for the benefit of customers any cumulative shortfall over the terms of the electric and gas rate plans between actual expenditures and the levels provided in rates. (i) In addition, amounts reflected in rates relating to income taxes and excess deferred federal income tax liability balances will be reconciled (i.e., refunded to or collected from customers) to any final, non-appealable NYSPSC-ordered findings in its investigation of O&R’s income tax accounting. See “Other Regulatory Matters,” in Note B. (j) Net plant reconciliation for AMI expenditures will be implemented for a single category of AMI capital expenditures that includes amounts allocated to both electric and gas customers. O&R New York – Gas Effective period November 2015 – October 2018 (a) January 2019 – December 2021 (d) Base rate changes Yr. 1 – $16.4 million – $16.4 million – $5.8 million – $10.6 million collected through a surcharge Yr. 1 – $(7.5) million (e) Amortization to income of net regulatory (assets) and liabilities Yr. 1 – $(1.7) million (b) – $(2.1) million (b) – $(2.5) million (b) Yr. 1 – $1.8 million (f) Other revenue sources Continuation of retention of annual revenues from non-firm customers of up to $4.0 million, with variances to be shared 80 percent by customers and 20 percent by company . Revenue decoupling mechanisms In 2015, 2016 2017 and 2018, the company deferred $0.8 million of regulatory assets, $6.2 million of regulatory liabilities, $1.7 million of regulatory liabilities and $6.3 million of regulatory liabilities, respectively. Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Current rate recovery of purchased gas costs. Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties (up to $3.7 million in Yr. 1, $4.7 million in Yr. 2 and $4.9 million in Yr. 3) if certain performance targets are not met. In 2015, 2016 and 2017, the company did not record any negative revenue adjustments. In 2018, the company recorded a $0.1 million negative revenue adjustment. Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $5.5 million; Yr. 2 - $5.7 million; and Yr. 3 - $6.0 million. Cost reconciliations In 2015 and 2016, the company deferred $4.5 million and $6.6 million as net regulatory liabilities and assets, respectively. In 2017 and 2018, the company deferred $3.5 million and $7.4 million as net regulatory liabilities, respectively. Reconciliation of expenses for pension and other postretirement benefits, environmental remediation costs, property taxes (g), energy efficiency program (h), the impact of new laws and certain other costs to amounts reflected in rates.(i) Net utility plant reconciliations Target levels reflected in rates are: Target levels reflected in rates were: Average rate base Yr. 1 – $366 million Yr. 1 – $454 million Weighted average cost of capital (after-tax) Yr. 1 – 7.10 percent Yr. 1 – 6.97 percent Authorized return on common equity 9.0 percent 9.00 percent Actual return on common equity Yr. 1 – 11.2 percent Earnings sharing Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets. In 2015, earnings did not exceed the earnings threshold. Actual earnings were $4 million, $0.2 million above the threshold for 2016 and 2017, respectively. In 2018, earnings did not exceed the earnings threshold. Most earnings above an annual earnings threshold of 9.6 percent are to be applied to reduce regulatory assets for environmental remediation and other costs accumulated in the rate year. Cost of long-term debt Yr. 1 – 5.42 percent Yr. 1 – 5.17 percent Common equity ratio 48 percent 48 percent (a) Rates pursuant to this rate plan continue in effect until a new rate plan is approved by the NYSPSC. (b) Reflects that the company will not recover from customers a total of approximately $14 million of regulatory assets for property tax and interest rate reconciliations. Amounts that will not be recovered from customers were charged-off in June 2015. (c) Excludes gas AMI as to which the company will be required to defer as a regulatory liability the revenue requirement impact of the amount, if any, by which actual average net utility plant balances are less than amounts reflected in rates: $0.5 million in year 1, $4.2 million in year 2 and $7.2 million in year 3. (d) If at the end of any year, Con Edison’s investments in its non-utility businesses exceed 15 percent of Con Edison’s total consolidated revenues, assets or cash flow, or if the ratio of holding company debt to total consolidated debt rises above 20 percent , O&R is required to notify the NYSPSC and submit a ring-fencing plan or a demonstration why additional ring-fencing measures (see Note S) are not necessary. (e) The Joint Proposal recommends that these base rate changes may be implemented with changes of: Yr. 1 - $(5.9) million ; Yr. 2 - $1.0 million ; and Yr. 3 - $1.0 million . Footnotes (f) through (j) to this table are the same as footnotes (f) through (j) to the table under “O&R New York - Electric,” above. RECO Effective period August 2014 – February 2017 March 2017 (a) Base rate changes Yr. 1 – $13.0 million Yr. 1 – $1.7 million Amortization to income of net regulatory (assets) and liabilities $0.4 million over three years and $(25.6) million of deferred storm costs over four years $0.2 million over three years and continuation of $(25.6) million of deferred storm costs over four years which expired on July 31, 2018 (b) Recoverable energy costs Current rate recovery of purchased power costs. Current rate recovery of purchased power costs. Cost reconciliations None None Average rate base $172.2 million Yr. 1 – $178.7 million Weighted average cost of capital (after-tax) 7.83 percent 7.47 percent Authorized return on common equity 9.75 percent 9.6 percent Actual return on common equity Yr. 1 – 9.2 percent Yr. 1 – 7.5 percent Cost of long-term debt 5.89 percent 5.37 percent Common equity ratio 50 percent 49.7 percent (a) Effective until a new rate plan approved by the NJBPU goes into effect. (b) In January 2016, the NJBPU approved RECO’s plan to spend $15.7 million in capital over three years to harden its electric system against storms, the costs of which RECO, beginning in 2017, is collecting through a custome
Schedule of Regulatory Assets	Regulatory Assets and Liabilities Regulatory assets and liabilities at December 31, 2018 and 2017 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Regulatory assets Unrecognized pension and other postretirement costs $2,238 $2,526 $2,111 $2,376 Environmental remediation costs 810 793 716 677 Revenue taxes 291 260 278 248 MTA power reliability deferral 229 50 229 50 Property tax reconciliation 101 51 86 25 Deferred storm costs 76 38 — — Pension and other postretirement benefits deferrals 73 79 56 58 Municipal infrastructure support costs 67 56 67 56 System peak reduction and energy efficiency programs 72 14 70 14 Brooklyn Queens demand management program 39 37 39 37 Unamortized loss on reacquired debt 36 37 34 35 Meadowlands heater odorization project 36 18 36 18 Preferred stock redemption 23 24 23 24 Recoverable REV demonstration project costs 20 19 18 17 Deferred derivative losses 17 44 11 37 Gate station upgrade project 17 13 17 13 Indian Point Energy Center program costs 13 29 13 29 Workers’ compensation 5 10 5 10 Recoverable energy costs 3 60 — 52 O&R transition bond charges 2 9 — — Surcharge for New York State assessment — 2 — 2 Other 126 97 114 85 Regulatory assets – noncurrent 4,294 4,266 3,923 3,863 Recoverable energy costs 40 27 35 25 Deferred derivative losses 36 40 29 37 Regulatory assets – current 76 67 64 62 Total Regulatory Assets $4,370 $4,333 $3,987 $3,925 Regulatory liabilities Future income tax* $2,515 $2,545 $2,363 $2,390 Allowance for cost of removal less salvage 928 846 790 719 TCJA net benefits 434 — 411 — Energy efficiency portfolio standard unencumbered funds 127 127 122 122 Net unbilled revenue deferrals 117 183 117 183 Pension and other postretirement benefit deferrals 62 207 40 181 Property tax refunds 45 44 45 44 Settlement of prudence proceeding 37 66 37 66 Property tax reconciliation 36 107 36 107 Earnings sharing - electric, gas and steam 36 29 27 19 System benefit charge carrying charge 27 12 24 11 Carrying charges on repair allowance and bonus depreciation 21 43 21 42 BQDM and REV Demo reconciliations 18 9 18 9 New York State income tax rate change 17 36 17 35 Settlement of gas proceedings 15 27 15 27 Base rate change deferrals 10 21 10 21 Unrecognized other postretirement costs 7 92 7 92 Net utility plant reconciliations 3 12 1 8 Variable-rate tax-exempt debt - cost rate reconciliation 1 30 1 26 Other 185 141 156 117 Regulatory liabilities – noncurrent 4,641 4,577 4,258 4,219 Revenue decoupling mechanism 53 29 36 21 Refundable energy costs 31 41 8 16 Deferred derivative gains 30 31 29 28 Regulatory liabilities—current 114 101 73 65 Total Regulatory Liabilities $4,755 $4,678 $4,331 $4,284 * See "Federal Income Tax" in Note A, "Other Regulatory Matters," above, and
Schedule of Regulatory Liabilities	Regulatory Assets and Liabilities Regulatory assets and liabilities at December 31, 2018 and 2017 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Regulatory assets Unrecognized pension and other postretirement costs $2,238 $2,526 $2,111 $2,376 Environmental remediation costs 810 793 716 677 Revenue taxes 291 260 278 248 MTA power reliability deferral 229 50 229 50 Property tax reconciliation 101 51 86 25 Deferred storm costs 76 38 — — Pension and other postretirement benefits deferrals 73 79 56 58 Municipal infrastructure support costs 67 56 67 56 System peak reduction and energy efficiency programs 72 14 70 14 Brooklyn Queens demand management program 39 37 39 37 Unamortized loss on reacquired debt 36 37 34 35 Meadowlands heater odorization project 36 18 36 18 Preferred stock redemption 23 24 23 24 Recoverable REV demonstration project costs 20 19 18 17 Deferred derivative losses 17 44 11 37 Gate station upgrade project 17 13 17 13 Indian Point Energy Center program costs 13 29 13 29 Workers’ compensation 5 10 5 10 Recoverable energy costs 3 60 — 52 O&R transition bond charges 2 9 — — Surcharge for New York State assessment — 2 — 2 Other 126 97 114 85 Regulatory assets – noncurrent 4,294 4,266 3,923 3,863 Recoverable energy costs 40 27 35 25 Deferred derivative losses 36 40 29 37 Regulatory assets – current 76 67 64 62 Total Regulatory Assets $4,370 $4,333 $3,987 $3,925 Regulatory liabilities Future income tax* $2,515 $2,545 $2,363 $2,390 Allowance for cost of removal less salvage 928 846 790 719 TCJA net benefits 434 — 411 — Energy efficiency portfolio standard unencumbered funds 127 127 122 122 Net unbilled revenue deferrals 117 183 117 183 Pension and other postretirement benefit deferrals 62 207 40 181 Property tax refunds 45 44 45 44 Settlement of prudence proceeding 37 66 37 66 Property tax reconciliation 36 107 36 107 Earnings sharing - electric, gas and steam 36 29 27 19 System benefit charge carrying charge 27 12 24 11 Carrying charges on repair allowance and bonus depreciation 21 43 21 42 BQDM and REV Demo reconciliations 18 9 18 9 New York State income tax rate change 17 36 17 35 Settlement of gas proceedings 15 27 15 27 Base rate change deferrals 10 21 10 21 Unrecognized other postretirement costs 7 92 7 92 Net utility plant reconciliations 3 12 1 8 Variable-rate tax-exempt debt - cost rate reconciliation 1 30 1 26 Other 185 141 156 117 Regulatory liabilities – noncurrent 4,641 4,577 4,258 4,219 Revenue decoupling mechanism 53 29 36 21 Refundable energy costs 31 41 8 16 Deferred derivative gains 30 31 29 28 Regulatory liabilities—current 114 101 73 65 Total Regulatory Liabilities $4,755 $4,678 $4,331 $4,284 * See "Federal Income Tax" in Note A, "Other Regulatory Matters," above, and

Capitalization (Tables)

Capitalization (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-Term Debt Maturities	Long-term debt maturing in the period 2019 - 2023 is as follows: (Millions of Dollars) Con Edison CECONY 2019 $650 $475 2020 866 350 2021 1,260 640 2022 413 — 2023 293 —
Carrying Amounts and Fair Values of Long-Term Debt	The carrying amounts and fair values of long-term debt at December 31, 2018 and 2017 are: (Millions of Dollars) 2018 2017 Long-Term Debt (including current portion) (a) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $18,145 $18,740 $16,029 $18,147 CECONY $14,151 $14,685 $13,625 $15,163 (a) Amounts shown are net of unamortized debt expense and unamortized debt discount of $185 million and $139 million for Con Edison and CECONY, respectively, as of December 31, 2018 and $142 million and $121 million for Con Edison and CECONY, respectively, as of December 31, 2017 .

Pension Benefits (Tables)

Pension Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Total Periodic Benefit Costs	The components of the Companies’ total periodic benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost – including administrative expenses $290 $263 $275 $272 $246 $258 Interest cost on projected benefit obligation 561 591 596 525 554 559 Expected return on plan assets (1,033) (968) (947) (979) (917) (898) Recognition of net actuarial loss 688 595 596 651 563 565 Recognition of prior service cost/(credit) (17) (17) 4 (19) (19) 2 TOTAL PERIODIC BENEFIT COST $489 $464 $524 $450 $427 $486 Cost capitalized (127) (181) (214) (119) (169) (203) Reconciliation to rate level (92) (34) 54 (100) (41) 58 Total expense recognized $270 $249 $364 $231 $217 $341 The components of the Companies’ total periodic postretirement benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost $20 $20 $18 $14 $13 $13 Interest cost on accumulated other postretirement benefit obligation 42 46 48 34 38 40 Expected return on plan assets (73) (69) (77) (63) (61) (67) Recognition of net actuarial loss/(gain) 8 2 5 3 (3) 3 Recognition of prior service cost/(credit) (6) (17) (20) (2) (11) (14) TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT) $(9) $(18) $(26) $(14) $(24) $(25) Cost capitalized (8) 8 11 (6) 10 10 Reconciliation to rate level 8 (4) 22 9 (2) 22 Total expense/(credit) recognized $(9) $(14) $7 $(11) $(16) $7
Schedule of Funded Status	The funded status at December 31, 2018 , 2017 and 2016 was as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN PROJECTED BENEFIT OBLIGATION Projected benefit obligation at beginning of year $15,536 $14,095 $14,377 $14,567 $13,203 $13,482 Service cost – excluding administrative expenses 286 259 271 267 241 254 Interest cost on projected benefit obligation 561 591 596 525 554 559 Net actuarial loss/(gain) (1,219) 1,231 (302) (1,159) 1,171 (282) Plan amendments — 6 (256) — — (259) Benefits paid (715) (646) (591) (658) (602) (551) PROJECTED BENEFIT OBLIGATION AT END OF YEAR $14,449 $15,536 $14,095 $13,542 $14,567 $13,203 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $14,274 $12,472 $11,759 $13,519 $11,815 $11,141 Actual return on plan assets (536) 2,041 829 (507) 1,935 787 Employer contributions 473 450 508 434 412 469 Benefits paid (715) (646) (591) (658) (602) (551) Administrative expenses (46) (43) (33) (44) (41) (31) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $13,450 $14,274 $12,472 $12,744 $13,519 $11,815 FUNDED STATUS $(999) $(1,262) $(1,623) $(798) $(1,048) $(1,388) Unrecognized net loss $2,464 $2,760 $3,157 $2,338 $2,624 $2,995 Unrecognized prior service costs (205) (223) (244) (222) (242) (258) Accumulated benefit obligation 13,030 13,897 12,655 12,161 12,972 11,806 The funded status of the programs at December 31, 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN BENEFIT OBLIGATION Benefit obligation at beginning of year $1,219 $1,198 $1,287 $985 $1,007 $1,093 Service cost 20 20 18 14 13 13 Interest cost on accumulated postretirement benefit obligation 42 46 48 34 38 40 Net actuarial loss/(gain) (70) 53 (57) (32) 16 (52) Benefits paid and administrative expenses, net of subsidies (135) (134) (134) (125) (124) (122) Participant contributions 38 36 36 37 35 35 BENEFIT OBLIGATION AT END OF YEAR $1,114 $1,219 $1,198 $913 $985 $1,007 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $1,039 $975 $994 $893 $851 $870 Actual return on plan assets (66) 150 60 (54) 130 52 Employer contributions 6 17 7 6 8 7 Employer group waiver plan subsidies 34 34 35 32 30 33 Participant contributions 37 35 36 37 35 35 Benefits paid (165) (172) (157) (155) (161) (146) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $885 $1,039 $975 $759 $893 $851 FUNDED STATUS $(229) $(180) $(223) $(154) $(92) $(156) Unrecognized net loss/(gain) $14 $(47) $(24) $(2) $(85) $(42) Unrecognized prior service costs (8) (14) (31) (5) (7) (18)
Schedule of Assumptions	The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount rate 4.25 % 3.70 % 4.25 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount rate 3.70 % 4.25 % 4.25 % Expected return on plan assets 7.50 % 7.50 % 7.80 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount Rate CECONY 4.15 % 3.55 % 4.00 % O&R 4.30 % 3.70 % 4.20 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount Rate CECONY 3.55 % 4.00 % 4.05 % O&R 3.70 % 4.20 % 4.20 % Expected Return on Plan Assets 7.50 % 7.50 % 7.00 %
Schedule of Expected Benefit Payments	Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years : (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $707 $726 $740 $755 $772 $4,072 CECONY 658 676 689 703 718 3,795 Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years , net of receipt of governmental subsidies: (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $80 $78 $76 $75 $74 $359 CECONY 70 67 65 64 63 302
Schedule of Plan Assets Allocations	The asset allocations for the pension plan at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 45% - 55% 51 % 58 % 58 % Debt Securities 33% - 43% 39 % 33 % 33 % Real Estate 10% -14% 10 % 9 % 9 % Total 100% 100 % 100 % 100 % The asset allocations for CECONY’s other postretirement benefit plans at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 42%-80% 52 % 60 % 60 % Debt Securities 20%-58% 48 % 40 % 40 % Total 100% 100 % 100 % 100 %
Schedule of Fair Value of Plan Assets	The fair values of the pension plan assets at December 31, 2018 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,515 $10 $3,525 International Equity (b) 2,896 — 2,896 U.S. Government Issued Debt (c) — 1,886 1,886 Corporate Bonds Debt (d) — 2,619 2,619 Structured Assets Debt (e) — 6 6 Other Fixed Income Debt (f) — 121 121 Cash and Cash Equivalents (g) 160 556 716 Futures (h) 568 — 568 Total investments within the fair value hierarchy $7,139 $5,198 $12,337 Investments measured at NAV per share (n) Private Equity (i) 440 Real Estate (j) 1,310 Hedge Funds (k) 255 Total investments valued using NAV per share $2,005 Funds for retiree health benefits (l) (118) (86) (204) Funds for retiree health benefits measured at NAV per share (l)(n) (33) Total funds for retiree health benefits $(237) Investments (excluding funds for retiree health benefits) $7,021 $5,112 $14,105 Pending activities (m) (655) Total fair value of plan net assets $13,450 (a) U.S. Equity includes both actively- and passively-managed assets with investments in domestic equity index funds and actively-managed small-capitalization equities. (b) International Equity includes international equity index funds and actively-managed international equities. (c) U.S. Government Issued Debt includes agency and treasury securities. (d) Corporate Bonds Debt consists of debt issued by various corporations. (e) Structured Assets Debt includes commercial-mortgage-backed securities and collateralized mortgage obligations. (f) Other Fixed Income Debt includes municipal bonds, sovereign debt and regional governments. (g) Cash and Cash Equivalents include short term investments, money markets, foreign currency and cash collateral. (h) Futures consist of exchange-traded financial contracts encompassing U.S. Equity, International Equity and U.S. Government indices. (i) Private Equity consists of global equity funds that are not exchange-traded. (j) Real Estate investments include real estate funds based on appraised values that are broadly diversified by geography and property type. (k) Hedge Funds are within a commingled structure which invests in various hedge fund managers who can invest in all financial instruments. (l) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note F. (m) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received and reflects adjustments for available estimates at year end. (n) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair values of the pension plan assets at December 31, 2017 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,872 $28 $3,900 International Equity (b) 4,132 — 4,132 U.S. Government Issued Debt (c) — 1,786 1,786 Corporate Bonds Debt (d) — 2,450 2,450 Structured Assets Debt (e) — 3 3 Other Fixed Income Debt (f) — 125 125 Cash and Cash Equivalents (g) 124 352 476 Futures (h) 308 — 308 Total investments within the fair value hierarchy $8,436 $4,744 $13,180 Investments measured at NAV per share (n) Private Equity (i) 336 Real Estate (j) 1,214 Hedge Funds (k) 251 Total investments valued using NAV per share $1,801 Funds for retiree health benefits (l) (168) (94) (262) Funds for retiree health benefits measured at NAV per share (l)(n) (36) Total funds for retiree health benefits $(298) Investments (excluding funds for retiree health benefits) $8,268 $4,650 $14,683 Pending activities (m) (409) Total fair value of plan net assets $14,274 (a) - (n) Reference is made to footnotes (a) through (n) in the above table of pension plan assets at December 31, 2018 by asset category. The fair values of the plans' assets at December 31, 2018 by asset category as defined by the accounting rules for fair value measurements (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $322 $322 Other Fixed Income Debt (b) — 289 289 Cash and Cash Equivalents (c) — 14 14 Total investments $— $625 $625 Funds for retiree health benefits (d) 118 86 204 Investments (including funds for retiree health benefits) $118 $711 $829 Funds for retiree health benefits measured at net asset value (d)(e) 33 Pending activities (f) 23 Total fair value of plan net assets $885 (a) Equity includes a passively managed commingled index fund benchmarked to the MSCI All Country World Index. (b) Other Fixed Income Debt includes a passively managed commingled index fund benchmarked to the Bloomberg Barclays U.S. Long Credit Index and an active separately managed fund indexed to the Bloomberg Barclays U.S. Long Credit Index. (c) Cash and Cash Equivalents include short term investments and money markets. (d) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note E. (e) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (f) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received, and reflects adjustments for available estimates at year end. The fair values of the plans' assets at December 31, 2017 by asset category (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $420 $420 Other Fixed Income Debt (b) — 286 286 Cash and Cash Equivalents (c) — 16 16 Total investments $— $722 $722 Funds for retiree health benefits (d) 168 94 262 Investments (including funds for retiree health benefits) $168 $816 $984 Funds for retiree health benefits measured at net asset value (d)(e) 36 Pending activities (f) 19 Total fair value of plan net assets $1,039 (a) - (f) Reference is made to footnotes (a) through (f) in the above table of other postretirement benefit plan assets at December 31, 2018 by asset category.
Schedule of Employer Contribution to Defined Savings Plan	The Companies also offer a defined contribution savings plan that covers substantially all employees and made contributions to the plan as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Con Edison $45 $40 $36 CECONY 39 35 32

Other Postretirement Benefits (

Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Net Periodic Benefit Costs	The components of the Companies’ total periodic benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost – including administrative expenses $290 $263 $275 $272 $246 $258 Interest cost on projected benefit obligation 561 591 596 525 554 559 Expected return on plan assets (1,033) (968) (947) (979) (917) (898) Recognition of net actuarial loss 688 595 596 651 563 565 Recognition of prior service cost/(credit) (17) (17) 4 (19) (19) 2 TOTAL PERIODIC BENEFIT COST $489 $464 $524 $450 $427 $486 Cost capitalized (127) (181) (214) (119) (169) (203) Reconciliation to rate level (92) (34) 54 (100) (41) 58 Total expense recognized $270 $249 $364 $231 $217 $341 The components of the Companies’ total periodic postretirement benefit costs for 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Service cost $20 $20 $18 $14 $13 $13 Interest cost on accumulated other postretirement benefit obligation 42 46 48 34 38 40 Expected return on plan assets (73) (69) (77) (63) (61) (67) Recognition of net actuarial loss/(gain) 8 2 5 3 (3) 3 Recognition of prior service cost/(credit) (6) (17) (20) (2) (11) (14) TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT) $(9) $(18) $(26) $(14) $(24) $(25) Cost capitalized (8) 8 11 (6) 10 10 Reconciliation to rate level 8 (4) 22 9 (2) 22 Total expense/(credit) recognized $(9) $(14) $7 $(11) $(16) $7
Schedule of Funded Status	The funded status at December 31, 2018 , 2017 and 2016 was as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN PROJECTED BENEFIT OBLIGATION Projected benefit obligation at beginning of year $15,536 $14,095 $14,377 $14,567 $13,203 $13,482 Service cost – excluding administrative expenses 286 259 271 267 241 254 Interest cost on projected benefit obligation 561 591 596 525 554 559 Net actuarial loss/(gain) (1,219) 1,231 (302) (1,159) 1,171 (282) Plan amendments — 6 (256) — — (259) Benefits paid (715) (646) (591) (658) (602) (551) PROJECTED BENEFIT OBLIGATION AT END OF YEAR $14,449 $15,536 $14,095 $13,542 $14,567 $13,203 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $14,274 $12,472 $11,759 $13,519 $11,815 $11,141 Actual return on plan assets (536) 2,041 829 (507) 1,935 787 Employer contributions 473 450 508 434 412 469 Benefits paid (715) (646) (591) (658) (602) (551) Administrative expenses (46) (43) (33) (44) (41) (31) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $13,450 $14,274 $12,472 $12,744 $13,519 $11,815 FUNDED STATUS $(999) $(1,262) $(1,623) $(798) $(1,048) $(1,388) Unrecognized net loss $2,464 $2,760 $3,157 $2,338 $2,624 $2,995 Unrecognized prior service costs (205) (223) (244) (222) (242) (258) Accumulated benefit obligation 13,030 13,897 12,655 12,161 12,972 11,806 The funded status of the programs at December 31, 2018 , 2017 and 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 CHANGE IN BENEFIT OBLIGATION Benefit obligation at beginning of year $1,219 $1,198 $1,287 $985 $1,007 $1,093 Service cost 20 20 18 14 13 13 Interest cost on accumulated postretirement benefit obligation 42 46 48 34 38 40 Net actuarial loss/(gain) (70) 53 (57) (32) 16 (52) Benefits paid and administrative expenses, net of subsidies (135) (134) (134) (125) (124) (122) Participant contributions 38 36 36 37 35 35 BENEFIT OBLIGATION AT END OF YEAR $1,114 $1,219 $1,198 $913 $985 $1,007 CHANGE IN PLAN ASSETS Fair value of plan assets at beginning of year $1,039 $975 $994 $893 $851 $870 Actual return on plan assets (66) 150 60 (54) 130 52 Employer contributions 6 17 7 6 8 7 Employer group waiver plan subsidies 34 34 35 32 30 33 Participant contributions 37 35 36 37 35 35 Benefits paid (165) (172) (157) (155) (161) (146) FAIR VALUE OF PLAN ASSETS AT END OF YEAR $885 $1,039 $975 $759 $893 $851 FUNDED STATUS $(229) $(180) $(223) $(154) $(92) $(156) Unrecognized net loss/(gain) $14 $(47) $(24) $(2) $(85) $(42) Unrecognized prior service costs (8) (14) (31) (5) (7) (18)
Schedule of Actuarial Assumptions	The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount rate 4.25 % 3.70 % 4.25 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount rate 3.70 % 4.25 % 4.25 % Expected return on plan assets 7.50 % 7.50 % 7.80 % Rate of compensation increase CECONY 4.25 % 4.25 % 4.25 % O&R 4.00 % 4.00 % 4.00 % The actuarial assumptions were as follows: 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations at December 31: Discount Rate CECONY 4.15 % 3.55 % 4.00 % O&R 4.30 % 3.70 % 4.20 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31: Discount Rate CECONY 3.55 % 4.00 % 4.05 % O&R 3.70 % 4.20 % 4.20 % Expected Return on Plan Assets 7.50 % 7.50 % 7.00 %
Schedule of Change of Assumed Health Care Cost Trend Rate	A one-percentage point change in the assumed health care cost trend rate would have the following effects at December 31, 2018 : Con Edison CECONY 1-Percentage-Point (Millions of Dollars) Increase Decrease Increase Decrease Effect on accumulated other postretirement benefit obligation $9 $11 $(18) $31 Effect on service cost and interest cost components for 2018 2 (1) (1) 1
Schedule of Expected Benefit Payments	Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years : (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $707 $726 $740 $755 $772 $4,072 CECONY 658 676 689 703 718 3,795 Based on current assumptions, the Companies expect to make the following benefit payments over the next ten years , net of receipt of governmental subsidies: (Millions of Dollars) 2019 2020 2021 2022 2023 2024-2028 Con Edison $80 $78 $76 $75 $74 $359 CECONY 70 67 65 64 63 302
Schedule of Plan Assets Allocations	The asset allocations for the pension plan at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 45% - 55% 51 % 58 % 58 % Debt Securities 33% - 43% 39 % 33 % 33 % Real Estate 10% -14% 10 % 9 % 9 % Total 100% 100 % 100 % 100 % The asset allocations for CECONY’s other postretirement benefit plans at the end of 2018 , 2017 and 2016 , and the target allocation for 2019 are as follows: Target Allocation Range Plan Assets at December 31, Asset Category 2019 2018 2017 2016 Equity Securities 42%-80% 52 % 60 % 60 % Debt Securities 20%-58% 48 % 40 % 40 % Total 100% 100 % 100 % 100 %
Schedule of Fair Value of Plan Assets	The fair values of the pension plan assets at December 31, 2018 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,515 $10 $3,525 International Equity (b) 2,896 — 2,896 U.S. Government Issued Debt (c) — 1,886 1,886 Corporate Bonds Debt (d) — 2,619 2,619 Structured Assets Debt (e) — 6 6 Other Fixed Income Debt (f) — 121 121 Cash and Cash Equivalents (g) 160 556 716 Futures (h) 568 — 568 Total investments within the fair value hierarchy $7,139 $5,198 $12,337 Investments measured at NAV per share (n) Private Equity (i) 440 Real Estate (j) 1,310 Hedge Funds (k) 255 Total investments valued using NAV per share $2,005 Funds for retiree health benefits (l) (118) (86) (204) Funds for retiree health benefits measured at NAV per share (l)(n) (33) Total funds for retiree health benefits $(237) Investments (excluding funds for retiree health benefits) $7,021 $5,112 $14,105 Pending activities (m) (655) Total fair value of plan net assets $13,450 (a) U.S. Equity includes both actively- and passively-managed assets with investments in domestic equity index funds and actively-managed small-capitalization equities. (b) International Equity includes international equity index funds and actively-managed international equities. (c) U.S. Government Issued Debt includes agency and treasury securities. (d) Corporate Bonds Debt consists of debt issued by various corporations. (e) Structured Assets Debt includes commercial-mortgage-backed securities and collateralized mortgage obligations. (f) Other Fixed Income Debt includes municipal bonds, sovereign debt and regional governments. (g) Cash and Cash Equivalents include short term investments, money markets, foreign currency and cash collateral. (h) Futures consist of exchange-traded financial contracts encompassing U.S. Equity, International Equity and U.S. Government indices. (i) Private Equity consists of global equity funds that are not exchange-traded. (j) Real Estate investments include real estate funds based on appraised values that are broadly diversified by geography and property type. (k) Hedge Funds are within a commingled structure which invests in various hedge fund managers who can invest in all financial instruments. (l) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note F. (m) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received and reflects adjustments for available estimates at year end. (n) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair values of the pension plan assets at December 31, 2017 by asset category are as follows: (Millions of Dollars) Level 1 Level 2 Total Investments within the fair value hierarchy U.S. Equity (a) $3,872 $28 $3,900 International Equity (b) 4,132 — 4,132 U.S. Government Issued Debt (c) — 1,786 1,786 Corporate Bonds Debt (d) — 2,450 2,450 Structured Assets Debt (e) — 3 3 Other Fixed Income Debt (f) — 125 125 Cash and Cash Equivalents (g) 124 352 476 Futures (h) 308 — 308 Total investments within the fair value hierarchy $8,436 $4,744 $13,180 Investments measured at NAV per share (n) Private Equity (i) 336 Real Estate (j) 1,214 Hedge Funds (k) 251 Total investments valued using NAV per share $1,801 Funds for retiree health benefits (l) (168) (94) (262) Funds for retiree health benefits measured at NAV per share (l)(n) (36) Total funds for retiree health benefits $(298) Investments (excluding funds for retiree health benefits) $8,268 $4,650 $14,683 Pending activities (m) (409) Total fair value of plan net assets $14,274 (a) - (n) Reference is made to footnotes (a) through (n) in the above table of pension plan assets at December 31, 2018 by asset category. The fair values of the plans' assets at December 31, 2018 by asset category as defined by the accounting rules for fair value measurements (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $322 $322 Other Fixed Income Debt (b) — 289 289 Cash and Cash Equivalents (c) — 14 14 Total investments $— $625 $625 Funds for retiree health benefits (d) 118 86 204 Investments (including funds for retiree health benefits) $118 $711 $829 Funds for retiree health benefits measured at net asset value (d)(e) 33 Pending activities (f) 23 Total fair value of plan net assets $885 (a) Equity includes a passively managed commingled index fund benchmarked to the MSCI All Country World Index. (b) Other Fixed Income Debt includes a passively managed commingled index fund benchmarked to the Bloomberg Barclays U.S. Long Credit Index and an active separately managed fund indexed to the Bloomberg Barclays U.S. Long Credit Index. (c) Cash and Cash Equivalents include short term investments and money markets. (d) The Companies set aside funds for retiree health benefits through a separate account within the pension trust, as permitted under Section 401(h) of the Internal Revenue Code of 1986, as amended. In accordance with the Code, the plan’s investments in the 401(h) account may not be used for, or diverted to, any purpose other than providing health benefits for retirees. The net assets held in the 401(h) account are calculated based on a pro-rata percentage allocation of the net assets in the pension plan. The related obligations for health benefits are not included in the pension plan’s obligations and are included in the Companies’ other postretirement benefit obligation. See Note E. (e) In accordance with ASU 2015-07, Fair Value Measurements (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its equivalent), certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. (f) Pending activities include security purchases and sales that have not settled, interest and dividends that have not been received, and reflects adjustments for available estimates at year end. The fair values of the plans' assets at December 31, 2017 by asset category (see Note P) are as follows: (Millions of Dollars) Level 1 Level 2 Total Equity (a) $— $420 $420 Other Fixed Income Debt (b) — 286 286 Cash and Cash Equivalents (c) — 16 16 Total investments $— $722 $722 Funds for retiree health benefits (d) 168 94 262 Investments (including funds for retiree health benefits) $168 $816 $984 Funds for retiree health benefits measured at net asset value (d)(e) 36 Pending activities (f) 19 Total fair value of plan net assets $1,039 (a) - (f) Reference is made to footnotes (a) through (f) in the above table of other postretirement benefit plan assets at December 31, 2018 by asset category.

Environmental Matters (Tables)

Environmental Matters (Tables)	12 Months Ended
	Dec. 31, 2018
Environmental Remediation Obligations [Abstract]
Accrued Liabilities and Regulatory Assets	The accrued liabilities and regulatory assets related to Superfund Sites at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Accrued Liabilities: Manufactured gas plant sites $689 $651 $603 $551 Other Superfund Sites 90 86 90 86 Total $779 $737 $693 $637 Regulatory assets $810 $793 $716 $677
Environmental Remediation Costs	Environmental remediation costs incurred related to Superfund Sites at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Remediation costs incurred $25 $24 $18 $19
Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings	The accrued liability for asbestos suits and workers’ compensation proceedings (including those related to asbestos exposure) and the amounts deferred as regulatory assets for the Companies at December 31, 2018 and 2017 were as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $79 $84 $75 $80 Regulatory assets – workers’ compensation $5 $10 $5 $10

Other Material Contingencies (T

Other Material Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Summary of Total Guarantees	A summary, by type and term, of Con Edison’s total guarantees under these other agreements at December 31, 2018 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $742 $404 $— $1,146 Energy transactions 462 20 201 683 Renewable electric production projects 137 — 403 540 Other 70 — — 70 Total $1,411 $424 $604 $2,439

Electricity Purchase Agreemen_2

Electricity Purchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2018
Regulated Operations [Abstract]
Summary of Estimated Capacity and Other Fixed Payments	The future capacity and other fixed payments under the electricity purchase agreements are estimated to be as follows: (Millions of Dollars) 2019 2020 2021 2022 2023 All Years Thereafter Con Edison $206 $117 $65 $54 $55 $601 CECONY 202 113 64 54 55 601
Summary of Capacity, Energy and Other Fixed Payments	The company’s payments under its agreements for capacity, energy and other fixed payments in 2018 , 2017 and 2016 were as follows: For the Years Ended December 31, (Millions of Dollars) 2018 2017 2016 Indian Point (a) $6 $211 $203 Linden Cogeneration (b) — 114 304 Astoria Energy (c) — — 50 Astoria Generating Company (d) 179 92 16 Brooklyn Navy Yard (e) 124 117 119 Cogen Technologies 9 18 — Total $318 $552 $692 (a) Contract term ended in 2018. (b) Contract term ended in 2017. (c) Contract term ended in 2016. (d) Capacity purchase agreements with terms ending in 2019, 2020 and 2021. (e) Contract for plant output, which started in 1996 and ends in 2036.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2018
Leases [Abstract]
Schedule of Capital Leases	The following assets under capital leases are included in the Companies’ consolidated balance sheets at December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 UTILITY PLANT Common $1 $2 $1 $1
Future Minimum Rental Payments for Operating Leases	The future minimum lease commitments under the Companies’ operating lease agreements that are not cancellable by the Companies are as follows: (Millions of Dollars) Con Edison CECONY 2019 $72 $56 2020 72 56 2021 71 54 2022 68 53 2023 68 53 All years thereafter 890 592 Total $1,241 $864

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax	The components of income tax are as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 State Current $(10) $(2) $(42) $6 $37 $(1) Deferred 107 103 188 82 75 114 Federal Current 3 (11) (43) (34) 73 59 Deferred 310 391 604 275 504 435 Amortization of investment tax credits (9) (9) (9) (3) (4) (4) Total income tax expense $401 $472 $698 $326 $685 $603
Schedule of Differences on Deferred Tax Assets and Liabilities	The tax effects of temporary differences, which gave rise to deferred tax assets and liabilities, are as follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Deferred tax liabilities: Property basis differences $7,402 $6,555 $6,446 $5,968 Regulatory assets: Unrecognized pension and other postretirement costs 627 697 591 656 Environmental remediation costs 227 219 200 187 Deferred storm costs 21 11 — — Other regulatory assets 273 269 252 241 Equity investments 102 263 — — Total deferred tax liabilities $8,652 $8,014 $7,489 $7,052 Deferred tax assets: Accrued pension and other postretirement costs $248 $264 $180 $187 Regulatory liabilities: Future income tax 702 698 662 660 Other regulatory liabilities 632 593 554 524 Superfund and other environmental costs 218 203 194 176 Asset retirement obligations 114 86 82 79 Loss carryforwards 229 95 — — Tax credits carryforward 817 658 — — Valuation allowance (33) (33) — — Other 53 112 102 148 Total deferred tax assets 2,980 2,676 1,774 1,774 Net deferred tax liabilities $5,672 $5,338 $5,715 $5,278 Unamortized investment tax credits 148 157 24 28 Net deferred tax liabilities and unamortized investment tax credits $5,820 $5,495 $5,739 $5,306
Schedule of Income Tax Reconciliation	Reconciliation of the difference between income tax expense and the amount computed by applying the prevailing statutory income tax rate to income before income taxes is as follows: Con Edison CECONY (% of Pre-tax income) 2018 2017 2016 2018 2017 2016 STATUTORY TAX RATE Federal 21 % 35 % 35 % 21 % 35 % 35 % Changes in computed taxes resulting from: State income tax 4 4 4 5 4 4 Cost of removal 1 1 (1 ) 1 1 (1 ) Other plant-related items (1 ) (1 ) — (1 ) (1 ) (1 ) TCJA deferred tax re-measurement 2 (13 ) — — — — Amortization of excess deferred federal income taxes (3 ) — — (3 ) — — Renewable energy credits (1 ) (1 ) (1 ) — — — Research and development credits — — (1 ) (1 ) — (1 ) Other — (2 ) — (1 ) (1 ) — Effective tax rate 23 % 23 % 36 % 21 % 38 % 36 %
Summary of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits for Con Edison and CECONY follows: Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Balance at January 1, $12 $42 $34 $5 $21 $2 Additions based on tax positions related to the current year 2 1 2 2 1 2 Additions based on tax positions of prior years 1 1 19 1 1 19 Reductions for tax positions of prior years (2) (24) (13) (1) (18) (2) Reductions from expiration of statute of limitations (4) (2) — — — — Settlements (3) (6) — (3) — — Balance at December 31, $6 $12 $42 $4 $5 $21

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock-Based Compensation Expense	The following table summarizes stock-based compensation expense recognized by the Companies in the years ended December 31, 2018 , 2017 and 2016 : Con Edison CECONY (Millions of Dollars) 2018 2017 2016 2018 2017 2016 Performance-based restricted stock $3 $53 $42 $3 $45 $36 Time-based restricted stock 2 2 2 1 2 2 Non-employee director deferred stock compensation 3 2 2 3 2 2 Stock purchase plan 6 6 4 6 6 4 Total $14 $63 $50 $13 $55 $44 Income tax benefit $4 $25 $20 $4 $22 $18
Assumptions Used to Calculate Fair Value of Awards	The assumptions used to calculate the fair value of the awards were as follows: 2018 2017 2016 Risk-free interest rate (a) 2.48% - 2.63% 1.76% - 1.89% 0.85% - 1.20% Expected term (b) 3 years 3 years 3 years Expected share price volatility (c) 14.76% - 17.71% 11.01% - 14.70% 17.72% - 18.22% (a) The risk-free rate is based on the U.S. Treasury zero-coupon yield curve. (b) The expected term of the Performance RSUs equals the vesting period. The Companies do not expect significant forfeitures to occur. (c) Based on historical experience.
Summary of Changes in Status of Performance RSUs	A summary of changes in the status of the Performance RSUs’ TSR and non-TSR portions during the year ended December 31, 2018 is as follows: Con Edison CECONY Weighted Average Grant Date Fair Value (a) Weighted Average Grant Date Fair Value (a) Units TSR Portion (b) Non-TSR Portion (c) Units TSR Portion (b) Non-TSR Portion (c) Non-vested at December 31, 2017 1,028,932 $71.74 $70.11 784,166 $71.06 $70.08 Granted 328,850 67.26 76.37 247,532 66.79 76.48 Vested (327,069) 57.77 63.27 (261,167) 57.37 63.18 Forfeited (24,877) 72.22 74.97 (20,877) 71.76 75.14 Transferred (d) — — — 12,252 78.47 72.71 Non-vested at December 31, 2018 1,005,836 $74.81 $74.27 761,906 $74.47 $74.42 (a) The TSR and non-TSR Portions each account for 50 percent of the awards’ value. (b) Fair value is determined using the Monte Carlo simulation described above. Weighted average grant date fair value does not reflect any accrual or payment of dividends prior to vesting. (c) Fair value is determined using the market price of one share of Con Edison common stock on the grant date. The market price has not been discounted to reflect that dividends do not accrue and are not payable on Performance RSUs until vesting. (d) Represents allocation to another Con Edison subsidiary of a portion of the Performance RSUs that had been awarded to a CECONY officer who transferred to another subsidiary.
Summary of Changes in Status of Time-Based Awards	A summary of changes in the status of time-based awards during the year ended December 31, 2018 is as follows: Con Edison CECONY Units Weighted Average Grant Date Fair Value Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 64,870 $71.93 61,420 $71.93 Granted 23,000 77.94 21,400 77.94 Vested (20,523) 61.03 (19,473) 61.03 Forfeited (2,167) 73.93 (1,967) 73.97 Non-vested at December 31, 2018 65,180 $77.42 61,380 $77.42

Financial Information by Busi_2

Financial Information by Business Segment (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Financial Data for Business Segments	The financial data for the business segments are as follows: As of and for the Year Ended December 31, 2018 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $7,971 $16 $984 $1,799 $(110) $519 $233 $31,012 $1,861 Gas 2,078 7 205 478 (23) 131 87 9,710 1,050 Steam 631 75 87 77 (10) 39 8 2,386 94 Consolidation adjustments — (98) — — — — — — — Total CECONY $10,680 $— $1,276 $2,354 ($143) $689 $328 $43,108 $3,005 O&R Electric $642 $— $56 $93 $(14) $25 $14 $2,036 $138 Gas 249 — 21 39 (5) 14 7 856 67 Other — — — — — — — — — Total O&R $891 $— $77 $132 $(19) $39 $21 $2,892 $205 Clean Energy Businesses $763 $— $85 $194 $33 $63 $19 $5,821 $1,791 Con Edison Transmission 4 — 1 (7) 91 20 (1) 1,425 248 Other (b) (1 ) — (1) (9) (24) 8 39 674 — Total Con Edison $12,337 $— $1,438 $2,664 $(62) $819 $406 $53,920 $5,249 As of and for the Year Ended December 31, 2017 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $7,972 $16 $925 $1,974 $(105) $472 $511 $29,661 $1,905 Gas 1,901 6 185 495 (23) 113 152 8,387 909 Steam 595 75 85 80 (9) 38 25 2,403 90 Consolidation adjustments — (97) — — — — — — — Total CECONY $10,468 $— $1,195 $2,549 $(137) $623 $688 $40,451 $2,904 O&R Electric $642 $— $51 $115 $(14) $24 $30 $1,949 $128 Gas 232 — 20 46 (5) 12 12 824 61 Other — — — — — — — — — Total O&R $874 $— $71 $161 $(19) $36 $42 $2,773 $189 Clean Energy Businesses $694 $— $74 $69 $33 $43 $(273) $2,735 $447 Con Edison Transmission 2 — 1 (8) 80 16 (11) 1,222 66 Other (b) (5) — — 3 (5) 11 13 930 — Total Con Edison $12,033 $— $1,341 $2,774 $(48) $729 $459 $48,111 $3,606 As of and for the Year Ended December 31, 2016 (Millions of Dollars) Operating revenues Inter- segment revenues Depreciation and amortization Operating income Other Income (deductions) Interest charges Income taxes on operating income (a) Total assets Capital expenditures CECONY Electric $8,106 $17 $865 $1,996 $(147) $459 $495 $30,708 $1,819 Gas 1,508 6 159 387 (31) 105 92 7,553 811 Steam 551 88 82 68 (11) 39 30 2,595 126 Consolidation adjustments — (111) — — — — — — — Total CECONY $10,165 $— $1,106 $2,451 $(189) $603 $617 $40,856 $2,756 O&R Electric $637 $— $49 $107 $(11) $24 $30 $1,949 $114 Gas 184 — 18 39 (4) 12 10 809 52 Other — — — — — — — — — Total O&R $821 $— $67 $146 $(15) $36 $40 $2,758 $166 Clean Energy Businesses $1,091 $7 $42 $183 $21 $34 $53 $2,551 $1,235 Con Edison Transmission — — — (3) 43 6 — 1,150 1,078 Other (b) (2) (7) 1 3 (1) 17 4 940 — Total Con Edison $12,075 $— $1,216 $2,780 $(141) $696 $714 $48,255 $5,235 (a) For Con Edison, the income tax expense/(benefit) on non-operating income was $(5) million , $13 million and $(16) million in 2018 , 2017 and 2016 , respectively. For CECONY, the income tax expense/(benefit) on non-operating income was $(2) million , $(3) million and $(14) million in 2018 , 2017 and 2016 , respectively. At December 31, 2017, Con Edison re-measured its deferred tax assets and liabilities based upon the 21 percent corporate income tax rate under the TCJA. As a result, Con Edison, decreased its federal income tax expense by $259 million ( $269 million , $11 million and $(21) million , respectively, for the Clean Energy Businesses, Con Edison Transmission and the parent company). See “Other Regulatory Matters” in Note B and Note L to the financial statements in Item 8. (b) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Offsetting of Assets	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at December 31, 2018 and 2017 were: (Millions of Dollars) 2018 2017 Balance Sheet Location Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Con Edison Fair value of derivative assets Current $43 $(14) $29 (b) $83 $(51) $32 (b) Noncurrent 14 (7) 7 (c) 10 (4) 6 Total fair value of derivative assets $57 $(21) $36 (b)(c) $93 $(55) $38 Fair value of derivative liabilities Current $(61) $11 $(50) $(67) $50 $(17) Noncurrent (19) 9 (10) (c) (43) 5 (38) Total fair value of derivative liabilities $(80) $20 $(60) $(110) $55 $(55) Net fair value derivative assets/(liabilities) $(23) $(1) $(24) (b)(c) $(17) $— $(17) (b) CECONY Fair value of derivative assets Current $25 $(6) $19 (b) $39 $(15) $24 (b) Noncurrent 11 (5) 6 9 (4) 5 Total fair value of derivative assets $36 $(11) $25 $48 $(19) $29 Fair value of derivative liabilities Current $(31) $6 $(25) $(26) $14 $(12) Noncurrent (12) 6 (6) (36) 4 (32) Total fair value of derivative liabilities $(43) $12 $(31) $(62) $18 $(44) Net fair value derivative assets/(liabilities) $(7) $1 $(6) (b) $(14) $(1) $(15) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At December 31, 2018 and 2017 , margin deposits for Con Edison ( $7 million and $12 million , respectively) and CECONY ( $6 million and $11 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include interest rate swaps of $2 million in noncurrent assets and $(6) million in noncurrent liabilities (see below).
Offsetting of Liabilities	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at December 31, 2018 and 2017 were: (Millions of Dollars) 2018 2017 Balance Sheet Location Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Gross Amounts of Recognized Assets/ (Liabilities) Gross Amounts Offset Net Amounts of Assets/(Liabilities) (a) Con Edison Fair value of derivative assets Current $43 $(14) $29 (b) $83 $(51) $32 (b) Noncurrent 14 (7) 7 (c) 10 (4) 6 Total fair value of derivative assets $57 $(21) $36 (b)(c) $93 $(55) $38 Fair value of derivative liabilities Current $(61) $11 $(50) $(67) $50 $(17) Noncurrent (19) 9 (10) (c) (43) 5 (38) Total fair value of derivative liabilities $(80) $20 $(60) $(110) $55 $(55) Net fair value derivative assets/(liabilities) $(23) $(1) $(24) (b)(c) $(17) $— $(17) (b) CECONY Fair value of derivative assets Current $25 $(6) $19 (b) $39 $(15) $24 (b) Noncurrent 11 (5) 6 9 (4) 5 Total fair value of derivative assets $36 $(11) $25 $48 $(19) $29 Fair value of derivative liabilities Current $(31) $6 $(25) $(26) $14 $(12) Noncurrent (12) 6 (6) (36) 4 (32) Total fair value of derivative liabilities $(43) $12 $(31) $(62) $18 $(44) Net fair value derivative assets/(liabilities) $(7) $1 $(6) (b) $(14) $(1) $(15) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At December 31, 2018 and 2017 , margin deposits for Con Edison ( $7 million and $12 million , respectively) and CECONY ( $6 million and $11 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include interest rate swaps of $2 million in noncurrent assets and $(6) million in noncurrent liabilities (see below).
Realized and Unrealized Gains or Losses on Commodity Derivatives	The following table presents the realized and unrealized gains or losses on commodity derivatives that have been deferred or recognized in earnings for the years ended December 31, 2018 and 2017 : Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2018 2017 2018 2017 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(1) $3 $1 $4 Noncurrent Deferred derivative gains 4 — 3 — Total deferred gains/(losses) $3 $3 $4 $4 Current Deferred derivative losses $4 $51 $8 $49 Current Recoverable energy costs (26) (154) (26) (144) Noncurrent Deferred derivative losses 27 4 26 5 Total deferred gains/(losses) $5 $(99) $8 $(90) Net deferred gains/(losses) $8 $(96) $12 $(86) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $— $— $— $— Gas purchased for resale (2) 3 — — Non-utility revenue 4 (a) 5 (b) — — Other operations and maintenance expense (2) (c) — (2) — Total pre-tax gain/(loss) recognized in income $— $8 $(2) $— (a) For the year ended December 31, 2018 , Con Edison recorded unrealized pre-tax losses in non-utility operating revenue ( $5 million ). (b) For the year ended December 31, 2017 , Con Edison recorded an immaterial unrealized pre-tax gain in non-utility operating revenue. (c) For the year ended December 31, 2018 , Con Edison recorded unrealized pre-tax losses in other operations and maintenance expense ( $2 million ).
Hedged Volume of Derivative Transactions	The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at December 31, 2018 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 28,303,678 18,519 164,668,697 3,780,000 CECONY 25,458,600 10,350 151,280,000 3,780,000 (a) Volumes are reported net of long and short positions, except natural gas collars where the volumes of long positions are reported. (b) Excludes electric congestion and gas basis swap contracts which are associated with electric and gas contracts and hedged volumes.
Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features	The following table presents the aggregate fair value of the Companies’ derivative instruments with credit-risk-related contingent features that are in a net liability position, the collateral posted for such positions and the additional collateral that would have been required to be posted had the lowest applicable credit rating been reduced one level and to below investment grade at December 31, 2018 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $36 $24 Collateral posted 6 — Additional collateral (b) (downgrade one level from current ratings) 6 2 Additional collateral (b)(c) (downgrade to below investment grade from current ratings) 66 37 (a) Non-derivative transactions for the purchase and sale of electricity and gas and qualifying derivative instruments, which have been designated as normal purchases or normal sales, are excluded from the table. These transactions primarily include purchases of electricity from independent system operators. In the event the Utilities and the Clean Energy Businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $1 million at December 31, 2018 . For certain other such non-derivative transactions, the Companies could be required to post collateral under certain circumstances, including in the event counterparties had reasonable grounds for insecurity. (b) The Companies measure the collateral requirements by taking into consideration the fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liabilities position plus amounts owed to counterparties for settled transactions and amounts required by counterparties for minimum financial security. The fair value amounts represent unrealized losses, net of any unrealized gains where the Companies have a legally enforceable right to offset. (c) Derivative instruments that are net assets have been excluded from the table. At December 31, 2018 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $20 million .

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2018 and 2017 are summarized below. 2018 2017 (Millions of Dollars) Level 1 Level 2 Level 3 Netting Adjustment (e) Total Level 1 Level 2 Level 3 Netting Adjustment (e) Total Con Edison Derivative assets: Commodity (a)(b)(c) $6 $36 $7 $(6) $43 $5 $77 $7 $(39) $50 Interest Rate Swaps (a)(b)(c)(f) — 2 — — 2 — — — — — Other (a)(b)(d) 287 114 — — 401 283 120 — — 403 Total assets $293 $152 $7 $(6) $446 $288 $197 $7 $(39) $453 Derivative liabilities: Commodity (a)(b)(c) $8 $43 $20 $(11) $60 $8 $93 $6 $(52) $55 Interest Rate Swaps (a)(b)(c)(f) — 6 — — 6 — — — — — Total liabilities $8 $49 $20 $(11) $66 $8 $93 $6 $(52) $55 CECONY Derivative assets: Commodity (a)(b)(c) $3 $28 $1 $(1) $31 $3 $40 $4 $(7) $40 Other (a)(b)(d) 267 109 — — 376 260 114 — — 374 Total assets $270 $137 $1 $(1) $407 $263 $154 $4 $(7) $414 Derivative liabilities: Commodity (a)(b)(c) $5 $30 $3 $(6) $32 $5 $57 $— $(18) $44 (a) The Companies’ policy is to review the fair value hierarchy and recognize transfers into and transfers out of the levels at the end of each reporting period. Con Edison and CECONY had $2 million of commodity derivative liabilities transferred from level 3 to level 2 during the year ended December 31, 2018 because of availability of observable market data due to the decrease in the terms of certain contracts from beyond three years as of December 31, 2017 to less than three years as of December 31, 2018 . Con Edison and CECONY had $11 million and $10 million , respectively, of commodity derivative liabilities transferred from level 3 to level 2 during the year ended December 31, 2017 because of availability of observable market data due to the decrease in the terms of certain contracts from beyond three years as of September 30, 2017 to less than three years as of December 31, 2017 . (b) Level 2 assets and liabilities include investments held in the deferred compensation plan and/or non-qualified retirement plans, exchange-traded contracts where there is insufficient market liquidity to warrant inclusion in Level 1, certain over-the-counter derivative instruments for electricity, refined products and natural gas. Derivative instruments classified as Level 2 are valued using industry standard models that incorporate corroborated observable inputs; such as pricing services or prices from similar instruments that trade in liquid markets, time value and volatility factors. (c) The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At December 31, 2018 and 2017 , the Companies determined that nonperformance risk would have no material impact on their financial position or results of operations. (d) Other assets are comprised of assets such as life insurance contracts within the deferred compensation plan and non-qualified retirement plans. (e) Amounts represent the impact of legally-enforceable master netting agreements that allow the Companies to net gain and loss positions and cash collateral held or placed with the same counterparties. (f) See Note O.
Schedule of Commodity Derivatives	Fair Value of Level 3 at December 31, 2018 (Millions of Dollars) Valuation Techniques Unobservable Inputs Range Con Edison — Commodity Electricity $(12) Discounted Cash Flow Forward energy prices (a) $21.34-$64.45 per MWh Discounted Cash Flow Forward capacity prices (a) $1.00-$6.30 per kW-month Natural Gas (2) Discounted Cash Flow Forward natural gas prices (a) $0.92-$6.62 per Dt Transmission Congestion Contracts 1 Discounted Cash Flow Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.29-$8.03 per MWh Total Con Edison — Commodity $(13) CECONY — Commodity Electricity $(3) Discounted Cash Flow Forward capacity prices (a) $1.00-$6.30 per kW-month Transmission Congestion Contracts 1 Discounted Cash Flow Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.49-$2.60 per MWh Total CECONY — Commodity $(2) (a) Generally, increases (decreases) in this input in isolation would result in a higher (lower) fair value measurement. (b) Generally, increases (decreases) in this input in isolation would result in a lower (higher) fair value measurement.
Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value	The table listed below provides a reconciliation of the beginning and ending net balances for assets and liabilities measured at fair value for the years ended December 31, 2018 and 2017 and classified as Level 3 in the fair value hierarchy: Con Edison CECONY (Millions of Dollars) 2018 2017 2018 2017 Beginning balance as of January 1, $1 $1 $4 $1 Included in earnings 4 8 4 2 Included in regulatory assets and liabilities (10) (13) (4) (7) Purchases — 2 — 1 Settlements (6) (8) (4) (3) Transfer out of level 3 (2) 11 (2) 10 Ending balance as of December 31, $(13) $1 $(2) $4

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Business Acquisitions, by Acquisition	At December 31, 2018 and 2017 , Con Edison’s consolidated balance sheet included the following amounts associated with its VIEs: Tax Equity Projects Great Valley Solar Copper Mountain - Mesquite Solar Texas Solar 4 (Millions of Dollars) 2018 2018 2018 2017 Restricted cash $— $— $4 $5 Non-utility property, less accumulated depreciation of $1 for each of the Tax Equity Projects and $15 and $12, for Texas Solar 4 in 2018 and 2017, respectively 313 492 98 101 Other assets 18 97 9 8 Total assets (a) $331 $589 $111 $114 Long-term debt due within one year $— $— $2 $2 Other liabilities 17 33 26 28 Long-term debt — — 56 58 Total liabilities (b) $17 $33 $84 $88 (a) The assets of the Tax Equity Projects and Texas Solar 4 represent assets of a consolidated VIE that can be used only to settle obligations of the consolidated VIE. (b) The liabilities of the Tax Equity Projects and Texas Solar 4 represent liabilities of a consolidated VIE for which creditors do not have recourse to the general credit of the primary beneficiary.
Summary of VIEs	The following table summarizes the VIEs into which Con Edison Development has entered as of December 31, 2018 : Project Name Generating Capacity (a) (MW AC) Power Purchase Agreement Term in Years Year of Investment Location Maximum Millions of Dollars ) (b) Great Valley Solar (c) 200 15-20 2018 California $281 Copper Mountain - Mesquite Solar (d) 344 20-25 2018 Nevada and Arizona 485 Texas Solar 4 32 25 2014 Texas 20 (a) Represents Con Edison Development’s ownership interest in the project. (b) Maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest ( $33 million for Great Valley Solar, $71 million for Copper Mountain - Mesquite Solar and $7 million for Texas Solar 4). Con Edison did not provide any financial or other support during the year that was not previously contractually required. (c) Great Valley Solar consists of the Great Valley Solar 1, Great Valley Solar 2, Great Valley Solar 3 and Great Valley Solar 4 projects. (d) Copper Mountain - Mesquite Solar consists of the Copper Mountain Solar 4, Mesquite Solar 2 and Mesquite Solar 3 projects.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Summary of Costs of Administrative and Other Services Provided and Received	The costs of administrative and other services provided by CECONY to, and received by it from, Con Edison and its other subsidiaries for the years ended December 31, 2018 , 2017 and 2016 were as follows: CECONY (Millions of Dollars) 2018 2017 2016 Cost of services provided $115 $111 $108 Cost of services received 73 64 64

Acquisitions, Investments and_2

Acquisitions, Investments and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Pro Forma Supplemental Information	Con Edison's revenues and net income for the years ended December 31, 2018 and 2017 as reported and pro forma to account on a consolidated basis for the acquisition as if the acquisition had been completed on January 1, 2017 instead of December 13, 2018 are as follows: Years ended December 31, (Millions of Dollars) 2018 2017 As Reported Revenue $12,337 $12,033 Net income 1,382 1,525 PRO FORMA SUPPLEMENTAL INFORMATION If Acquired January 1, 2017 (a)(b) Revenue $12,655 $12,331 Net income 1,279 1,612 (a) Reflects the following material adjustments: • included additional interest expense of $37 million and $38 million in 2018 and 2017, respectively, that would have been incurred if $825 million that was borrowed in December 2018 under a variable rate term loan agreement to fund a portion of the purchase price for the acquisition had instead been borrowed for such purpose on January 1, 2017 at a fixed rate of 4.64% per annum; and • with respect to the Previously-Owned JV Interests: eliminated the $131 million purchase accounting gain (pre-tax) that Con Edison recognized upon the completion of the acquisition in 2018 and reflected the $131 million purchase accounting gain in 2017; recorded the corresponding increase to the book value of the related net utility plant and power purchase agreement intangible asset as of January 1, 2017 instead of December 13, 2018, and included the increased depreciation and amortization expense in 2018 and 2017; and eliminated $33 million and $32 million of other income that Con Edison had recorded in 2018 and 2017, respectively, under the equity method of accounting. (b) Recalculating each investor’s claim on the investee’s assets under the contractual liquidation waterfall as if the acquisition had been completed on January 1, 2017 is impracticable. Accordingly, no HLBV adjustments were made.

General (Details)

General (Details)	12 Months Ended
	Dec. 31, 2018subsidiaryregistrant
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of registrants | registrant	2
Number of regulated subsidiaries | subsidiary	2

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Other Matters - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 11,928
Total revenues	12,337	$ 12,033	$ 12,075
CECONY
Disaggregation of Revenue [Line Items]
Total revenues	10,680	10,468	10,165
Operating segment | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	424
Total revenues	763	694	1,091
Operating segment | Con Edison Transmission
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	4
Total revenues	4	2	0
Operating segment | CECONY
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	10,597
Total revenues	10,680	10,468	10,165
Operating segment | O&R
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	903
Total revenues	891	874	821
Operating segment | Electric | CECONY
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	7,920
Total revenues	7,971	7,972	8,106
Operating segment | Electric | O&R
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	647
Total revenues	642	642	637
Operating segment | Gas | CECONY
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	2,052
Total revenues	2,078	1,901	1,508
Operating segment | Gas | O&R
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	256
Total revenues	249	232	184
Operating segment | Steam | CECONY
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	625
Total revenues	631	595	551
Operating segment | Renewables | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	329
Total revenues	329
Operating segment | Energy services | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	95
Total revenues	95
Operating segment | Other | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0
Total revenues	339
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	0
Total revenues	(1)	(5)	(2)
Other | O&R
Disaggregation of Revenue [Line Items]
Total revenues	0	$ 0	$ 0
Other
Disaggregation of Revenue [Line Items]
Total revenues	409
Other | Operating segment | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Total revenues	339
Other | Operating segment | Con Edison Transmission
Disaggregation of Revenue [Line Items]
Total revenues	0
Other | Operating segment | CECONY
Disaggregation of Revenue [Line Items]
Total revenues	83
Other | Operating segment | O&R
Disaggregation of Revenue [Line Items]
Total revenues	(12)
Other | Operating segment | Electric | CECONY
Disaggregation of Revenue [Line Items]
Total revenues	51
Other | Operating segment | Electric | O&R
Disaggregation of Revenue [Line Items]
Total revenues	(5)
Other | Operating segment | Gas | CECONY
Disaggregation of Revenue [Line Items]
Total revenues	26
Other | Operating segment | Gas | O&R
Disaggregation of Revenue [Line Items]
Total revenues	(7)
Other | Operating segment | Steam | CECONY
Disaggregation of Revenue [Line Items]
Total revenues	6
Other | Operating segment | Renewables | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Total revenues	0
Other | Operating segment | Energy services | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Total revenues	0
Other | Operating segment | Other | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Total revenues	339
Other | Other
Disaggregation of Revenue [Line Items]
Total revenues	(1)
Engineering, procurement and construction | Renewables | Clean Energy Businesses
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 103

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Other Matters - Change in Unbilled Contract and Unearned Revenues (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Unbilled contract revenue
Beginning balance	$ 58
Additions	144
Subtractions	173
Ending balance	29
Unearned revenue
Beginning balance	87
Additions	38
Subtractions	105
Ending balance	20
Contracts with customer, revenue recognized, amount outstanding end of last period	$ 50

Summary of Significant Accoun_6

Summary of Significant Accounting Policies and Other Matters - Revenue Recognition, Remaining Performance Obligation (Details) $ in Millions	Dec. 31, 2018USD ($)
Accounting Policies [Abstract]
Remaining performance obligation	$ 95
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Accounting Policies [Abstract]
Remaining performance obligation	$ 59
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected timing of satisfaction	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Accounting Policies [Abstract]
Remaining performance obligation	$ 36
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected timing of satisfaction

Summary of Significant Accoun_7

Summary of Significant Accounting Policies and Other Matters - Schedule of Total Excise Taxes Recorded in Operating Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Excise Taxes [Line Items]
Excise taxes	$ 330	$ 302	$ 336
CECONY
Schedule of Excise Taxes [Line Items]
Excise taxes	$ 318	$ 292	$ 316

Summary of Significant Accoun_8

Summary of Significant Accounting Policies and Other Matters - Other Receivables (Details) $ in Millions	Dec. 31, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables from third parties related with power restoration	$ 104
CECONY
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables from third parties related with power restoration	$ 98

Summary of Significant Accoun_9

Summary of Significant Accounting Policies and Other Matters - Plant and Depreciation (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Public Utility, Property, Plant and Equipment [Line Items]
Accumulated amortization		$ 29	$ 15
Annual aggregate depreciation allowance		1,323
Software Licenses
Public Utility, Property, Plant and Equipment [Line Items]
Gross asset		100
Amortization period	15 years
Estimated aggregate annual amortization expense	$ 7
Accumulated amortization		$ 3
Non-Utility Plant | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		3 years
Non-Utility Plant | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		30 years
CECONY
Public Utility, Property, Plant and Equipment [Line Items]
AFUDC rates (percent)		5.40%	5.50%	4.70%
Average depreciation rates (percent)		3.10%	3.10%	3.10%
Annual aggregate depreciation allowance		$ 1,253
CECONY | Software Licenses
Public Utility, Property, Plant and Equipment [Line Items]
Gross asset		$ 95
CECONY | Electric | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
CECONY | Electric | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		95 years
CECONY | Gas | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
CECONY | Gas | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		100 years
CECONY | Steam | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
CECONY | Steam | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		80 years
CECONY | General Plant | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
CECONY | General Plant | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		55 years
O&R
Public Utility, Property, Plant and Equipment [Line Items]
AFUDC rates (percent)		2.20%	2.50%	3.50%
Average depreciation rates (percent)		2.90%	2.90%	2.90%
O&R | Electric | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
O&R | Electric | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		75 years
O&R | Gas | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
O&R | Gas | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		75 years
O&R | General Plant | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		5 years
O&R | General Plant | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated useful lives (years)		50 years

Summary of Significant Accou_10

Summary of Significant Accounting Policies and Other Matters - Capitalized Cost of Utility Plant (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Public Utility, Property, Plant and Equipment [Line Items]
General	$ 3,331	$ 3,008
Held for future use	76	76
Construction work in progress	1,978	1,605
NET UTILITY PLANT	37,580	35,273
Electric Generation
Public Utility, Property, Plant and Equipment [Line Items]
Generation	593	544
Electric Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	3,333	3,210
Electric Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	19,750	18,959
Gas
Public Utility, Property, Plant and Equipment [Line Items]
Gas	7,714	6,976
Steam
Public Utility, Property, Plant and Equipment [Line Items]
Steam	1,830	1,798
General
Public Utility, Property, Plant and Equipment [Line Items]
General	2,306	2,105
CECONY
Public Utility, Property, Plant and Equipment [Line Items]
General	3,056	2,753
Held for future use	67	67
Construction work in progress	1,850	1,502
NET UTILITY PLANT	35,370	33,205
CECONY | Electric Generation
Public Utility, Property, Plant and Equipment [Line Items]
Generation	592	544
CECONY | Electric Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	3,106	2,990
CECONY | Electric Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	18,716	17,996
CECONY | Gas
Public Utility, Property, Plant and Equipment [Line Items]
Gas	7,107	6,403
CECONY | Steam
Public Utility, Property, Plant and Equipment [Line Items]
Steam	1,830	1,798
CECONY | General
Public Utility, Property, Plant and Equipment [Line Items]
General	$ 2,102	$ 1,905

Summary of Significant Accou_11

Summary of Significant Accounting Policies and Other Matters - Goodwill (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Accounting Policies [Abstract]
Goodwill, impairment charge	$ 0

Summary of Significant Accou_12

Summary of Significant Accounting Policies and Other Matters - Long-Lived and Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2018USD ($)MW	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ 29,000,000	$ 15,000,000
Amortization of intangible assets	14,000,000	9,000,000	$ 2,000,000
Amortization expense, 2019	105,000,000
Amortization expense, 2020	105,000,000
Amortization expense, 2021	105,000,000
Amortization expense, 2022	105,000,000
Amortization expense, 2023	105,000,000
Asset impairment	2,000,000
Impairment charges on long-lived assets		0	0
Impairment charges on intangible assets		0	$ 0
Long-term debt	18,145,000,000	16,029,000,000
Net non-utility plant	41,749,000,000	37,600,000,000
Intangible assets	1,654,000,000	131,000,000
PG&E Project
Finite-Lived Intangible Assets [Line Items]
Long-term debt	1,050,000,000
Net non-utility plant	885,000,000
Intangible assets	$ 1,125,000,000
PG&E Project | Con Edison Development
Finite-Lived Intangible Assets [Line Items]
Aggregate power to be sold (in MW) | MW	680
PG&E Project | Secured Related to Project Debt
Finite-Lived Intangible Assets [Line Items]
Net non-utility plant	$ 292,000,000
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	3,000,000
Accumulated amortization	7,000,000	6,000,000
Power Purchase Agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	1,712,000,000	131,000,000
Accumulated amortization	$ 22,000,000	$ 9,000,000

Summary of Significant Accou_13

Summary of Significant Accounting Policies and Other Matters - Recoverable Energy Costs (Details)	12 Months Ended
	Dec. 31, 2018
Minimum
Public Utilities, General Disclosures [Line Items]
Recovery or refund of energy costs, deferral period	1 month
Maximum
Public Utilities, General Disclosures [Line Items]
Recovery or refund of energy costs, deferral period	2 months

Summary of Significant Accou_14

Summary of Significant Accounting Policies and Other Matters - Investments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 0	$ 467
Supplemental retirement income plan assets	326	330
Deferred income plan assets	75	73
Other	2	9
Total investments	1,766	2,001
CET | Stagecoach Gas Services, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	948	971
CET | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	363	98
CET | New York Transco, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	52	53
CECONY
Schedule of Equity Method Investments [Line Items]
Equity method investments	0	0
Supplemental retirement income plan assets	301	301
Deferred income plan assets	75	73
Other	9	9
Total investments	385	383
CECONY | CET | Stagecoach Gas Services, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	0	0
CECONY | CET | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	0	0
CECONY | CET | New York Transco, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 0	$ 0

Summary of Significant Accou_15

Summary of Significant Accounting Policies and Other Matters - Pension and Other Postretirement Benefits (Details)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Investment gains and losses recognized, time period (years)	15 years
Other actuarial gains and losses recognized, time period (years)	10 years
Difference between fair value and expected market related value of plan assets (percent)	20.00%

Summary of Significant Accou_16

Summary of Significant Accounting Policies and Other Matters - Research and Development Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Research and Development Expenses [Line Items]
Research and development costs	$ 24	$ 24	$ 24
CECONY
Research and Development Expenses [Line Items]
Research and development costs	$ 23	$ 23	$ 22

Summary of Significant Accou_17

Summary of Significant Accounting Policies and Other Matters - Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Net income	$ 1,382	$ 1,525	$ 1,245
Weighted average common shares outstanding – basic (in shares)	311.7	307.1	300.4
Add: Incremental shares attributable to effect of potentially dilutive securities (in shares)	1.2	1.7	1.5
Adjusted weighted average common shares outstanding – diluted (in shares)	312.9	308.8	301.9
Net income per common share — basic (in dollars per share)	$ 4.43	$ 4.97	$ 4.15
Net income per common share — diluted (in dollars per share)	$ 4.42	$ 4.94	$ 4.12

Summary of Significant Accou_18

Summary of Significant Accounting Policies and Other Matters - Changes in Accumulated Other Comprehensive Income/(Loss) by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE AS OF BEGINNING OF PERIOD	$ 15,425	$ 14,306	$ 13,061
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	10	1	7
BALANCE AS OF END OF PERIOD	16,839	15,425	14,306
Accumulated OCI
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE AS OF BEGINNING OF PERIOD	(26)	(27)	(34)
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	10	1	7
BALANCE AS OF END OF PERIOD	(16)	(26)	(27)
Pension Plan Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
OCI before reclassifications, net of tax	4	(4)	2
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	6	5	5
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	10	1	7
OCI before reclassifications, tax	3	3	(1)
Amounts reclassified from accumulated OCI related to pension plan liabilities, tax	(2)	(3)	(3)
CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2
CECONY | Accumulated OCI
AOCI Attributable to Parent, Net of Tax [Roll Forward]
BALANCE AS OF BEGINNING OF PERIOD	(6)	(7)	(9)
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2
BALANCE AS OF END OF PERIOD	(5)	(6)	(7)
CECONY | Pension Plan Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
OCI before reclassifications, net of tax	0	0	1
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	1	1	1
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	$ 1	1	2
OCI before reclassifications, tax		(1)	1
Amounts reclassified from accumulated OCI related to pension plan liabilities, tax		$ (1)	$ (1)

Summary of Significant Accou_19

Summary of Significant Accounting Policies and Other Matters - Reconciliation of Cash, Temporary Investments and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and Cash Equivalents [Line Items]
Cash and temporary cash investments	$ 895	$ 797
Restricted cash	111	47
Total cash, temporary cash investments and restricted cash	1,006	844	$ 830
CECONY
Cash and Cash Equivalents [Line Items]
Cash and temporary cash investments	818	730
Restricted cash	0	0
Total cash, temporary cash investments and restricted cash	818	730	$ 704	$ 859
Con Edison Development
Cash and Cash Equivalents [Line Items]
Restricted cash	109	46
RECO | Transition Bond
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 2	$ 1

Regulatory Matters - Summary of

Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Electric) (Details) - USD ($)	1 Months Ended	12 Months Ended					36 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2019	Dec. 31, 2016
Public Utilities, General Disclosures [Line Items]
Revenues		$ 12,337,000,000	$ 12,033,000,000	$ 12,075,000,000
Deferred revenues		20,000,000	87,000,000
Deferred revenues		$ (514,000,000)	(598,000,000)
NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues		15.00%
Maximum | NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues		15.00%
Percentage of debt to total consolidated debt		20.00%
CECONY
Public Utilities, General Disclosures [Line Items]
Revenues		$ 10,680,000,000	10,468,000,000	10,165,000,000
Deferred revenues		(392,000,000)	(454,000,000)
CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities				123,000,000
Retention of annual transmission congestion revenues								$ 90,000,000
Actual earnings adjustment mechanism incentives		25,000,000	13,000,000
Other earnings incentives		5,000,000	5,000,000
Deferred revenues	$ 101,000,000		45,000,000	101,000,000	$ 98,000,000	$ 146,000,000		101,000,000
Deferred revenues		(6,000,000)
Negative revenue adjustments		0	0	0	0	5,000,000
Cost reconciliation, deferred net regulatory liabilities	68,000,000			68,000,000	26,000,000	57,000,000		$ 68,000,000
Cost reconciliation, deferred net regulatory assets		189,000,000	35,000,000
Net utility plant reconciliations		(400,000)	400,000	9,000,000	(17,000,000)	(6,000,000)
Earnings sharing, threshold limit		$ 0	$ 0	6,500,000	$ 44,400,000	$ 0
Earnings sharing, positive adjustment				5,700,000
Common equity ratio (percent)								48.00%
Base rate change deferral regulatory liability impact	0			0				$ 0
Increase in gas base rate due to expiration of temporary credit under the prior rate plan	48,000,000
Deferrals for property taxes limitation from rates (percent)								90.00%
Recovery deferral (percent)		80.00%
Maximum deferral (percent)		30.00%
CECONY | Electric | Deferred storm costs
Public Utilities, General Disclosures [Line Items]
Amortization of regulatory asset								$ 107,000,000
Decrease in recoverable property damage costs								4,000,000
CECONY | Electric | Service Termination
Public Utilities, General Disclosures [Line Items]
Revenues		$ 3,000,000
CECONY | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Retention of annual transmission congestion revenues							$ 75,000,000
Authorized return on common equity (percent)							9.00%
Earnings sharing (percent)							9.50%
Common equity ratio (percent)							48.00%
Recovery or refund of energy costs, deferral period							10 years
CECONY | Electric | Scenario, Forecast | NYSPSC
Public Utilities, General Disclosures [Line Items]
Base rate changes							$ 199,000,000
CECONY | Electric | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ (76,200,000)			$ (76,200,000)				(76,200,000)
Amortization to income of net regulatory (assets) and liabilities								(37,000,000)
Average rate base								$ 17,323,000,000
Weighted average cost of capital (after-tax) (percent)								7.05%
Authorized return on common equity (percent)								9.20%
Actual return on common equity (percent)								9.04%
Earnings sharing (percent)	9.80%			9.80%				9.80%
Cost of long-term debt (percent)	5.17%			5.17%				5.17%
Deferral, annual maximum (not more than) (percent)								5.00%
CECONY | Electric | Year 1 | Transmission and distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 16,869,000,000
CECONY | Electric | Year 1 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								89,000,000
CECONY | Electric | Year 1 | Other
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								2,034,000,000
CECONY | Electric | Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)								400,000,000
CECONY | Electric | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							195,000,000
Amortization to income of net regulatory (assets) and liabilities							84,000,000
Potential earnings adjustment mechanism incentives							28,000,000
Potential penalties (annually)							376,000,000
Average rate base							$ 18,902,000,000
Weighted average cost of capital (after-tax) (percent)							6.82%
Actual return on common equity (percent)							9.30%
Cost of long-term debt (percent)							4.93%
Recovery of energy efficiency and savings program costs							$ 20,500,000
CECONY | Electric | Year 1 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							21,689,000,000
CECONY | Electric | Year 1 | Scenario, Forecast | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							126,000,000
CECONY | Electric | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 124,000,000			$ 124,000,000				124,000,000
Amortization to income of net regulatory (assets) and liabilities								(37,000,000)
Average rate base								$ 18,113,000,000
Weighted average cost of capital (after-tax) (percent)								7.08%
Authorized return on common equity (percent)								9.20%
Actual return on common equity (percent)								10.16%
Earnings sharing (percent)	9.80%			9.80%				9.80%
Cost of long-term debt (percent)	5.23%			5.23%				5.23%
Deferral, annual maximum (not more than) (percent)								7.50%
CECONY | Electric | Year 2 | Transmission and distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 17,401,000,000
CECONY | Electric | Year 2 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								177,000,000
CECONY | Electric | Year 2 | Other
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								2,102,000,000
CECONY | Electric | Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)								400,000,000
CECONY | Electric | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							155,000,000
Amortization to income of net regulatory (assets) and liabilities							83,000,000
Potential earnings adjustment mechanism incentives							47,000,000
Potential penalties (annually)							341,000,000
Average rate base							$ 19,530,000,000
Weighted average cost of capital (after-tax) (percent)							6.80%
Actual return on common equity (percent)							9.36%
Cost of long-term debt (percent)							4.88%
Recovery of energy efficiency and savings program costs							$ 49,000,000
CECONY | Electric | Year 2 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							22,338,000,000
CECONY | Electric | Year 2 | Scenario, Forecast | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							257,000,000
CECONY | Electric | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 0			$ 0				0
Amortization to income of net regulatory (assets) and liabilities								123,000,000
Average rate base								$ 18,282,000,000
Weighted average cost of capital (after-tax) (percent)								6.91%
Authorized return on common equity (percent)								9.00%
Actual return on common equity (percent)								9.66%
Earnings sharing (percent)	9.60%			9.60%				9.60%
Cost of long-term debt (percent)	5.09%			5.09%				5.09%
Deferral, annual maximum (not more than) (percent)								10.00%
CECONY | Electric | Year 3 | Transmission and distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 17,929,000,000
CECONY | Electric | Year 3 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								268,000,000
CECONY | Electric | Year 3 | Other
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								2,069,000,000
CECONY | Electric | Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)								$ 400,000,000
CECONY | Electric | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							155,000,000
Amortization to income of net regulatory (assets) and liabilities							69,000,000
Potential earnings adjustment mechanism incentives							64,000,000
Potential penalties (annually)							352,000,000
Average rate base							$ 20,277,000,000
Weighted average cost of capital (after-tax) (percent)							6.73%
Cost of long-term debt (percent)							4.74%
Recovery of energy efficiency and savings program costs							$ 107,500,000
CECONY | Electric | Year 3 | Scenario, Forecast | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							23,002,000,000
CECONY | Electric | Year 3 | Scenario, Forecast | Advanced metering infrastructure (AMI)
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							$ 415,000,000

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) customer in Thousands, $ in Millions	Apr. 01, 2018USD ($)	Jan. 31, 2022USD ($)	Jan. 31, 2021USD ($)	Jan. 31, 2019USD ($)	Nov. 30, 2018USD ($)	Aug. 31, 2018USD ($)	Mar. 31, 2018USD ($)customer	Dec. 31, 2017USD ($)	Apr. 30, 2017USD ($)	Dec. 31, 2018USD ($)	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 31, 2022
Public Utilities, General Disclosures [Line Items]
Regulatory assets								$ 4,333		$ 4,370			$ 4,370		$ 4,333		$ 4,370	$ 4,333
Net benefit of the TCJA																		(259)
Regulatory liabilities								4,577		4,641			4,641		4,577		4,641	4,577
Utilities
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	434
Future Income Tax
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	54	3,713
Regulatory liabilities								2,545		2,515			2,515		2,545		2,515	2,545
Accelerated Tax Depreciation Benefits
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																		2,684
Net Unbilled Revenue Deferrals
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities								183		117			117		$ 183		117	183
RECO | Electric | Hurricane
Public Utilities, General Disclosures [Line Items]
Number of customers affected with interrupted service | customer							44
Restoration costs													17
RECO | FERC
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount									$ 17.7			$ 11.8
Return on common equity (percent)															10.00%
Increase in regulatory liability resulting from TCJA							$ 28
Amount of customer refund to reflect TCJA					$ 0.6
Impact in regulatory liability resulting from TCJA, subject to normalization requirements							$ 16
RECO | NJBPU | Electric
Public Utilities, General Disclosures [Line Items]
Approved interim rate decrease	$ 2.9
Net benefit of the TCJA											$ 1
CECONY
Public Utilities, General Disclosures [Line Items]
Regulatory assets								3,925		3,987			3,987		$ 3,925		3,987	3,925
Regulatory liabilities								4,219		4,258			4,258		4,219		4,258	4,219
CECONY | Future Income Tax
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA								3,513									49	3,513
Regulatory liabilities								2,390		2,363			2,363		2,390		2,363	2,390
CECONY | Accelerated Tax Depreciation Benefits
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	2,593	2,542
CECONY | Deferred Income Tax Charge, Amortized Over Remaining Life of Asset
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	969
CECONY | Net Unbilled Revenue Deferrals
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities								183		117			117		$ 183		117	$ 183
CECONY | Electric | Hurricane
Public Utilities, General Disclosures [Line Items]
Number of customers affected with interrupted service | customer							209
Restoration costs													133
Operation and maintenance expenses													15
Operation and maintenance expenses charged against a storm reserve													83
Capital expenditures										29			29				29
Removal costs													6
CECONY | NYSPSC | Electric
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA						$ 2,516
Income tax benefit to be credited to customers resulting from TCJA										307
CECONY | NYSPSC | Gas
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	841
Income tax benefit to be credited to customers resulting from TCJA										90
CECONY | NYSPSC | Steam
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	$ 193
Income tax benefit to be credited to customers resulting from TCJA										6				$ 15
Tax credit, amortization period, protected portion																	3 years
CECONY | NYSPSC | MTA Subway Power Outage
Public Utilities, General Disclosures [Line Items]
Regulatory costs										260			260				$ 260
Regulatory assets										229			229				229
CECONY | NYSPSC | Scenario, Forecast | Electric
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA																$ 259
CECONY | NYSPSC | Scenario, Forecast | Gas
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA																113
CECONY | NYSPSC | Scenario, Forecast | Steam
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA																$ 25
CECONY | NYSPSC | Electric | MTA Subway Power Outage
Public Utilities, General Disclosures [Line Items]
Regulatory costs										31			31				31
CECONY | NYSPSC | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 263	$ 352
Return on common equity (percent)																			9.75%
Common equity ratio (percent)																			50.00%
CECONY | NYSPSC | Electric | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount				$ 485
Return on common equity (percent)				9.75%
Common equity ratio (percent)				50.00%
Proposed EAM (percent)				1.00%
CECONY | NYSPSC | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount		$ 155	$ 138
Return on common equity (percent)																			9.75%
Common equity ratio (percent)																			50.00%
CECONY | NYSPSC | Gas | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount				$ 210
Return on common equity (percent)				9.75%
Common equity ratio (percent)				50.00%
Proposed EAM (percent)				0.70%
O&R | Future Income Tax
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA								$ 161									2
O&R | Accelerated Tax Depreciation Benefits
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	128
O&R | Deferred Income Tax Charge, Amortized Over Remaining Life of Asset
Public Utilities, General Disclosures [Line Items]
Increase in regulatory liability resulting from TCJA																	$ 35
O&R | Electric | Hurricane
Public Utilities, General Disclosures [Line Items]
Number of customers affected with interrupted service | customer							93
Restoration costs													$ 43
O&R | NYSPSC | Electricity and Gas
Public Utilities, General Disclosures [Line Items]
Income tax benefit to be credited to customers resulting from TCJA										$ 22
Tax credit, amortization period, protected portion										3 years
Tax credit, amortization period, unprotected portion										15 years

Regulatory Matters - Summary _2

Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Gas) (Details) - USD ($)	1 Months Ended	12 Months Ended					36 Months Ended
	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2019	Dec. 31, 2016
Public Utilities, General Disclosures [Line Items]
Revenues		$ 12,337,000,000	$ 12,033,000,000	$ 12,075,000,000
Deferred revenues		20,000,000	87,000,000
CECONY
Public Utilities, General Disclosures [Line Items]
Revenues		10,680,000,000	10,468,000,000	10,165,000,000
CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities								$ 4,000,000
Regulatory liabilities, amortization period								3 years
Amount of revenues retained	$ 65,000,000			65,000,000	$ 66,000,000	$ 70,000,000		$ 65,000,000
Percentage of revenue reserve								15.00%
Other earnings incentives		6,000,000	7,000,000
Deferred revenues	71,000,000	12,000,000	3,000,000	71,000,000	54,000,000	28,000,000		$ 71,000,000
Negative revenue adjustments		0	5,000,000	0	0	0
Cost reconciliation, deferred net regulatory liabilities	$ 32,000,000		2,000,000	$ 32,000,000	11,000,000	38,000,000		$ 32,000,000
Cost reconciliation, deferred net regulatory assets		44,000,000
Net utility plant reconciliations		2,200,000	2,200,000		1,000,000
Earnings sharing (percent)	9.90%			9.90%				9.90%
Earnings sharing, threshold limit		0	$ 0	$ 0	0	0
Common equity ratio (percent)								48.00%
Base rate change deferral regulatory liability impact	$ 32,000,000			32,000,000				$ 32,000,000
Increase in gas base rate due to expiration of temporary credit under the prior rate plan	41,000,000
Difference in property taxes (percent)								90.00%
CECONY | Gas | Maximum
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained	$ 65,000,000			65,000,000				$ 65,000,000
Potential penalties (annually)				$ 56,000,000	$ 44,000,000	$ 33,000,000
CECONY | Gas | Gas Leak Backlog, Leak Prone Pipe and Service Terminations
Public Utilities, General Disclosures [Line Items]
Revenues		$ 5,000,000
CECONY | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Percentage of revenue reserve							15.00%
Earnings sharing (percent)							9.50%
Common equity ratio (percent)							48.00%
Deferral, annual maximum (not more than) (percent)							10.00%
CECONY | Gas | Scenario, Forecast | Maximum
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained							$ 65,000,000
CECONY | Gas | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes								(54,600,000)
Average rate base								$ 3,521,000,000
Weighted average cost of capital (after-tax) (percent)								7.10%
Authorized return on common equity (percent)								9.30%
Actual return on common equity (percent)								8.02%
Cost of long-term debt (percent)	5.17%			5.17%				5.17%
CECONY | Gas | Year 1 | Gas delivery
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 3,899,000,000
CECONY | Gas | Year 1 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								3,000,000
CECONY | Gas | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							(5,000,000)
Amortization to income of net regulatory (assets) and liabilities							39,000,000
Potential incentives if performance targets are met							7,000,000
Potential penalties (annually)							68,000,000
Average rate base							$ 4,841,000,000
Weighted average cost of capital (after-tax) (percent)							6.82%
Authorized return on common equity (percent)							9.00%
Actual return on common equity (percent)							9.22%
Cost of long-term debt (percent)							4.93%
CECONY | Gas | Year 1 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							$ 5,844,000,000
CECONY | Gas | Year 1 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							27,000,000
CECONY | Gas | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes								38,600,000
Average rate base								$ 3,863,000,000
Weighted average cost of capital (after-tax) (percent)								7.13%
Actual return on common equity (percent)								8.13%
Cost of long-term debt (percent)	5.23%			5.23%				5.23%
CECONY | Gas | Year 2 | Gas delivery
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 4,258,000,000
CECONY | Gas | Year 2 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								8,000,000
CECONY | Gas | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							92,000,000
Amortization to income of net regulatory (assets) and liabilities							37,000,000
Potential incentives if performance targets are met							8,000,000
Potential penalties (annually)							63,000,000
Average rate base							$ 5,395,000,000
Weighted average cost of capital (after-tax) (percent)							6.80%
Actual return on common equity (percent)							9.04%
Cost of long-term debt (percent)							4.88%
CECONY | Gas | Year 2 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							$ 6,512,000,000
CECONY | Gas | Year 2 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							57,000,000
CECONY | Gas | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes								56,800,000
Average rate base								$ 4,236,000,000
Weighted average cost of capital (after-tax) (percent)								7.21%
Actual return on common equity (percent)								7.83%
Cost of long-term debt (percent)	5.39%			5.39%				5.39%
CECONY | Gas | Year 3 | Gas delivery
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 4,698,000,000
CECONY | Gas | Year 3 | Storm hardening
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations								$ 30,000,000
CECONY | Gas | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes							90,000,000
Amortization to income of net regulatory (assets) and liabilities							36,000,000
Potential incentives if performance targets are met							8,000,000
Potential penalties (annually)							70,000,000
Average rate base							$ 6,005,000,000
Weighted average cost of capital (after-tax) (percent)							6.73%
Cost of long-term debt (percent)							4.74%
CECONY | Gas | Year 3 | Scenario, Forecast | Gas average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							$ 7,177,000,000
CECONY | Gas | Year 3 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations							$ 100,000,000

Regulatory Matters - Summary _3

Regulatory Matters - Summary of Utilities Rate Plans (CECONY-Steam) (Details) - CECONY - Steam - USD ($)	12 Months Ended					36 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities						$ 37,000,000
Regulatory liabilities, amortization period						3 years
Negative revenue adjustments	$ 0	$ 0	$ 0	$ 0	$ 0
Cost reconciliation, deferred net regulatory liabilities	(1,000,000)	14,000,000	$ 8,000,000		42,000,000	$ 8,000,000
Cost reconciliation, deferred net regulatory assets				17,000,000
Net utility plant reconciliations	0	0			100,000
Authorized return on common equity (percent)						9.30%
Earnings sharing (percent)			9.90%			9.90%
Earnings sharing, threshold limit	$ 14,200,000	8,500,000	$ 7,800,000	$ 11,500,000	$ 0
Earnings sharing, positive adjustment		$ 1,100,000	4,000,000
Common equity ratio (percent)						48.00%
Other regulatory liabilities			$ 8,000,000			$ 8,000,000
Difference in property taxes (percent)						90.00%
Deferral, annual maximum (not more than) (percent)						10.00%
Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes						$ (22,400,000)
Average rate base						$ 1,511,000,000
Weighted average cost of capital (after-tax) (percent)						7.10%
Actual return on common equity (percent)						9.82%
Cost of long-term debt (percent)			5.17%			5.17%
Year 1 | Production
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,752,000,000
Year 1 | Distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						6,000,000
Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						1,000,000
Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes						19,800,000
Average rate base						$ 1,547,000,000
Weighted average cost of capital (after-tax) (percent)						7.13%
Actual return on common equity (percent)						10.88%
Cost of long-term debt (percent)			5.23%			5.23%
Year 2 | Production
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,732,000,000
Year 2 | Distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						11,000,000
Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						1,000,000
Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes						20,300,000
Average rate base						$ 1,604,000,000
Weighted average cost of capital (after-tax) (percent)						7.21%
Actual return on common equity (percent)						10.54%
Cost of long-term debt (percent)			5.39%			5.39%
Year 3 | Production
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,720,000,000
Year 3 | Distribution
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						25,000,000
Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						1,000,000
Year 4
Public Utilities, General Disclosures [Line Items]
Base rate changes						$ 0
Actual return on common equity (percent)						9.51%
Year 5
Public Utilities, General Disclosures [Line Items]
Base rate changes						$ 0
Actual return on common equity (percent)						11.73%

Regulatory Matters - Summary _4

Regulatory Matters - Summary of Utilities Rate Plans (O&R New York-Electric) (Details) - USD ($)	12 Months Ended				24 Months Ended	36 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2017	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
Deferred revenues	$ 20,000,000	$ 87,000,000
Deferred revenues	$ 514,000,000	598,000,000
NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues	15.00%
Percentage of debt to total consolidated debt	20.00%
Maximum | NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues	15.00%
O&R | Electric
Public Utilities, General Disclosures [Line Items]
Deferred revenues			$ 6,300,000	$ 0
Deferred revenues	$ 500,000	11,200,000
Negative revenue adjustments	0	0	0	1,250,000
Deferral of net increase (decrease) to regulatory assets	5,000,000	3,200,000	7,400,000	300,000
Net utility plant reconciliations	$ 1,400,000	(1,900,000)	(1,900,000)	$ 2,200,000
Authorized return on common equity (percent)					9.00%
Earnings sharing (percent)					9.60%
Earnings sharing, threshold limit		$ 300,000	$ 6,100,000
Common equity ratio (percent)					48.00%
Deferred storm and property reserve deficiency, noncurrent					$ 59,300,000
Deferred storm and property reserve deficiency, recovery period					5 years
Deferred storm and property reserve deficiency not recovered					$ 1,000,000
O&R | Electric | Property Tax and Interest Rate Reconciliations
Public Utilities, General Disclosures [Line Items]
Regulatory assets not recoverable					4,000,000
O&R | Electric | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes					9,300,000
Amortization to income of net regulatory assets					(8,500,000)
Net utility plant reconciliations					928,000,000
Average rate base					$ 763,000,000
Weighted average cost of capital (after-tax) (percent)					7.10%
Actual return on common equity (percent)					10.80%
Cost of long-term debt (percent)					5.42%
Deferred storm and property reserve deficiency, noncurrent					$ 11,850,000
Rate exclusion amount with balance below regulatory threshold					1,000,000
O&R | Electric | Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					4,000,000
O&R | Electric | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes					8,800,000
Amortization to income of net regulatory assets					(9,400,000)
Net utility plant reconciliations					970,000,000
Average rate base					$ 805,000,000
Weighted average cost of capital (after-tax) (percent)					7.06%
Actual return on common equity (percent)					9.70%
Cost of long-term debt (percent)					5.35%
Deferred storm and property reserve deficiency, noncurrent					$ 11,850,000
Rate exclusion amount with balance below regulatory threshold					9,000,000
O&R | Electric | Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					4,000,000
O&R | Electric | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes					0
Amortization to income of net regulatory assets					0
Average rate base					$ 805,000,000
Weighted average cost of capital (after-tax) (percent)					7.06%
Actual return on common equity (percent)					7.20%
Cost of long-term debt (percent)					5.35%
O&R | Electric | Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					$ 4,000,000
O&R | Electric | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Authorized return on common equity (percent)						9.00%
Earnings sharing (percent)						9.60%
Common equity ratio (percent)						48.00%
Deferrals for property taxes limitation from rates (percent)						90.00%
O&R | Electric | Scenario, Forecast | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes						$ 13,400,000
Amortization to income of net regulatory assets						(1,500,000)
Potential earnings adjustment mechanism incentives						3,600,000
Potential incentive if target is met, related to service terminations						500,000
Average rate base						$ 878,000,000
Weighted average cost of capital (after-tax) (percent)						6.97%
Cost of long-term debt (percent)						5.17%
Requested rate increase (decrease), amount						$ 8,600,000
Deferral, annual maximum (not more than) (percent)						0.10%
O&R | Electric | Scenario, Forecast | Year 1 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,008,000,000
O&R | Electric | Scenario, Forecast | Year 1 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						48,000,000
O&R | Electric | Scenario, Forecast | Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						4,000,000
O&R | Electric | Scenario, Forecast | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes						8,000,000
Amortization to income of net regulatory assets						(1,500,000)
Potential earnings adjustment mechanism incentives						4,000,000
Potential incentive if target is met, related to service terminations						500,000
Average rate base						$ 906,000,000
Weighted average cost of capital (after-tax) (percent)						6.96%
Cost of long-term debt (percent)						5.14%
Requested rate increase (decrease), amount						$ 12,100,000
Deferral, annual maximum (not more than) (percent)						0.075%
O&R | Electric | Scenario, Forecast | Year 2 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,032,000,000
O&R | Electric | Scenario, Forecast | Year 2 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						58,000,000
O&R | Electric | Scenario, Forecast | Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						4,000,000
O&R | Electric | Scenario, Forecast | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes						5,800,000
Amortization to income of net regulatory assets						(1,500,000)
Potential earnings adjustment mechanism incentives						4,200,000
Potential incentive if target is met, related to service terminations						500,000
Average rate base						$ 948,000,000
Weighted average cost of capital (after-tax) (percent)						6.96%
Cost of long-term debt (percent)						5.14%
Requested rate increase (decrease), amount						$ 12,200,000
Deferral, annual maximum (not more than) (percent)						0.05%
O&R | Electric | Scenario, Forecast | Year 3 | Electric average excluding AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						$ 1,083,000,000
O&R | Electric | Scenario, Forecast | Year 3 | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations						61,000,000
O&R | Electric | Scenario, Forecast | Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						$ 5,000,000

Regulatory Matters - Summary _5

Regulatory Matters - Summary of Utilities Rate Plans (O&R New York-Gas) (Details) - USD ($)	12 Months Ended				36 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2021	Oct. 31, 2018
Public Utilities, General Disclosures [Line Items]
Deferred revenues	$ 514,000,000	$ 598,000,000
Deferred revenues	$ 20,000,000	87,000,000
NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues	15.00%
Percentage of debt to total consolidated debt	20.00%
Maximum | NYSPSC
Public Utilities, General Disclosures [Line Items]
Percentage of total consolidated revenues	15.00%
O&R | Gas
Public Utilities, General Disclosures [Line Items]
Deferred revenues				$ 800,000
Deferred revenues	$ 6,300,000	1,700,000	$ 6,200,000
Negative revenue adjustments	100,000	0	0	0
Cost reconciliation, deferred net regulatory liabilities	7,400,000	3,500,000		4,500,000
Cost reconciliation, deferred net regulatory assets			6,600,000
Net utility plant reconciliations	$ 400,000	0	0	$ 0
Authorized return on common equity (percent)						9.00%
Earnings sharing (percent)						9.60%
Earnings sharing, threshold limit		$ 200,000	$ 4,000,000
Common equity ratio (percent)						48.00%
O&R | Gas | Property Tax and Interest Rate Reconciliations
Public Utilities, General Disclosures [Line Items]
Regulatory assets not recoverable						$ 14,000,000
O&R | Gas | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Amount of revenues retained					$ 4,000,000
Share in variances in annual revenue retained (percent)					20.00%
Potential earnings adjustment mechanism incentives					$ 300,000
Authorized return on common equity (percent)					9.00%
Earnings sharing (percent)					9.60%
Common equity ratio (percent)					48.00%
O&R | Gas | Scenario, Forecast | Customers
Public Utilities, General Disclosures [Line Items]
Share in variances in annual revenue retained (percent)					80.00%
O&R | Gas | Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes						16,400,000
Amortization to income of net regulatory assets						(1,700,000)
Net utility plant reconciliations						492,000,000
Average rate base						$ 366,000,000
Weighted average cost of capital (after-tax) (percent)						7.10%
Actual return on common equity (percent)						11.20%
Cost of long-term debt (percent)						5.42%
Rate exclusion amount with balance below regulatory threshold						$ 500,000
O&R | Gas | Year 1 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						3,700,000
O&R | Gas | Year 1 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					$ (7,500,000)
Amortization to income of net regulatory assets					1,800,000
Potential earnings adjustment mechanism incentives					1,200,000
Net utility plant reconciliations					593,000,000
Average rate base					$ 454,000,000
Weighted average cost of capital (after-tax) (percent)					6.97%
Cost of long-term debt (percent)					5.17%
Requested rate increase (decrease), amount					$ (5,900,000)
O&R | Gas | Year 1 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					20,000,000
O&R | Gas | Year 1 | Scenario, Forecast | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					5,500,000
O&R | Gas | Year 2
Public Utilities, General Disclosures [Line Items]
Base rate changes						16,400,000
Amortization to income of net regulatory assets						(2,100,000)
Net utility plant reconciliations						518,000,000
Average rate base						$ 391,000,000
Weighted average cost of capital (after-tax) (percent)						7.06%
Actual return on common equity (percent)						9.70%
Cost of long-term debt (percent)						5.35%
Rate exclusion amount with balance below regulatory threshold						$ 4,200,000
O&R | Gas | Year 2 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						4,700,000
O&R | Gas | Year 2 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					3,600,000
Amortization to income of net regulatory assets					1,800,000
Potential earnings adjustment mechanism incentives					1,300,000
Net utility plant reconciliations					611,000,000
Average rate base					$ 476,000,000
Weighted average cost of capital (after-tax) (percent)					6.96%
Cost of long-term debt (percent)					5.14%
Requested rate increase (decrease), amount					$ 1,000,000
O&R | Gas | Year 2 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					24,000,000
O&R | Gas | Year 2 | Scenario, Forecast | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					5,700,000
O&R | Gas | Year 3
Public Utilities, General Disclosures [Line Items]
Base rate changes						5,800,000
Base rate change through surcharge						10,600,000
Amortization to income of net regulatory assets						(2,500,000)
Net utility plant reconciliations						546,000,000
Average rate base						$ 417,000,000
Weighted average cost of capital (after-tax) (percent)						7.06%
Actual return on common equity (percent)						8.00%
Cost of long-term debt (percent)						5.35%
Rate exclusion amount with balance below regulatory threshold						$ 7,200,000
O&R | Gas | Year 3 | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)						$ 4,900,000
O&R | Gas | Year 3 | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Base rate changes					700,000
Amortization to income of net regulatory assets					1,800,000
Potential earnings adjustment mechanism incentives					1,300,000
Net utility plant reconciliations					632,000,000
Average rate base					$ 498,000,000
Weighted average cost of capital (after-tax) (percent)					6.96%
Cost of long-term debt (percent)					5.14%
Requested rate increase (decrease), amount					$ 1,000,000
O&R | Gas | Year 3 | Scenario, Forecast | AMI
Public Utilities, General Disclosures [Line Items]
Net utility plant reconciliations					25,000,000
O&R | Gas | Year 3 | Scenario, Forecast | Maximum
Public Utilities, General Disclosures [Line Items]
Potential penalties (annually)					$ 6,000,000

Regulatory Matters - Summary _6

Regulatory Matters - Summary of Utilities Rate Plans (RECO) (Details) - RECO - USD ($) $ in Millions	1 Months Ended	31 Months Ended
	Mar. 31, 2017	Feb. 28, 2017
Public Utilities, General Disclosures [Line Items]
Amortization to income of net regulatory (assets) and liabilities	$ 0.2	$ 0.4
Regulatory liabilities, amortization period	3 years	3 years
Amortization to income of net regulatory assets	$ (25.6)	$ (25.6)
Regulatory assets, amortization period	4 years	4 years
Average rate base	$ 178.7	$ 172.2
Weighted average cost of capital (after-tax) (percent)	7.47%	7.83%
Authorized return on common equity (percent)	9.60%	9.75%
Cost of long-term debt (percent)	5.37%	5.89%
Common equity ratio (percent)	49.70%	50.00%
Electric
Public Utilities, General Disclosures [Line Items]
Plan electric system storm hardening amount	$ 15.7
Plan period (years)	3 years
Year 1
Public Utilities, General Disclosures [Line Items]
Base rate changes	$ 1.7	$ 13
Actual return on common equity (percent)	7.50%	9.20%
Year 2
Public Utilities, General Disclosures [Line Items]
Actual return on common equity (percent)		8.70%

Regulatory Matters - Regulatory

Regulatory Matters - Regulatory Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	$ 4,294	$ 4,266
Regulatory assets – current	76	67
Total Regulatory Assets	4,370	4,333
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,238	2,526
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	810	793
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	291	260
MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	229	50
Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	101	51
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	76	38
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	73	79
Municipal infrastructure support costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	67	56
System peak reduction and energy efficiency programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	72	14
Brooklyn Queens demand management program
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	39	37
Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	36	37
Meadowlands heater odorization project
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	36	18
Preferred stock redemption
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	23	24
Recoverable REV demonstration project costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	20	19
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	17	44
Gate Station Upgrade Project [Member]
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	17	13
Indian Point Energy Center program costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	13	29
Workers’ compensation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5	10
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	3	60
Regulatory assets – current	40	27
O&R transition bond charges
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2	9
Surcharge for New York State assessment
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	2
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	126	97
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – current	36	40
CECONY
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	3,923	3,863
Regulatory assets – current	64	62
Total Regulatory Assets	3,987	3,925
CECONY | Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,111	2,376
CECONY | Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	716	677
CECONY | Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	278	248
CECONY | MTA power reliability deferral
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	229	50
CECONY | Property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	86	25
CECONY | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	0
CECONY | Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	56	58
CECONY | Municipal infrastructure support costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	67	56
CECONY | System peak reduction and energy efficiency programs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	70	14
CECONY | Brooklyn Queens demand management program
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	39	37
CECONY | Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	34	35
CECONY | Meadowlands heater odorization project
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	36	18
CECONY | Preferred stock redemption
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	23	24
CECONY | Recoverable REV demonstration project costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	18	17
CECONY | Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	11	37
CECONY | Gate Station Upgrade Project [Member]
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	17	13
CECONY | Indian Point Energy Center program costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	13	29
CECONY | Workers’ compensation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	5	10
CECONY | Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	52
Regulatory assets – current	35	25
CECONY | O&R transition bond charges
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	0
CECONY | Surcharge for New York State assessment
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	2
CECONY | Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	114	85
CECONY | Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – current	$ 29	$ 37

Regulatory Matters - Regulato_2

Regulatory Matters - Regulatory Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Regulatory Liabilities [Line Items]
Regulatory assets	$ 4,294	$ 4,266
Regulatory liabilities – noncurrent	4,641	4,577
Regulatory liabilities—current	114	101
Total Regulatory Liabilities	4,755	4,678
Future income tax
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	2,515	2,545
Allowance for cost of removal less salvage
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	928	846
TCJA net benefits
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	434	0
Energy efficiency portfolio standard unencumbered funds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	127	127
Net unbilled revenue deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	117	183
Pension and other postretirement benefit deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	62	207
Property tax refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	45	44
Settlement of prudence proceeding
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	37	66
Property tax reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	107
Earnings sharing - electric, gas and steam
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	29
System benefit charge carrying charge
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	27	12
Carrying charges on repair allowance and bonus depreciation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	21	43
BQDM and REV Demo reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	18	9
New York State income tax rate change
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	17	36
Settlement of gas proceedings
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	15	27
Base rate change deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	21
Unrecognized other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	7	92
Net utility plant reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	3	12
Variable-rate tax-exempt debt - cost rate reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1	30
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	185	141
Revenue decoupling mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	53	29
Refundable energy costs
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	31	41
Deferred derivative gains
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	30	31
CECONY
Regulatory Liabilities [Line Items]
Regulatory assets	3,923	3,863
Regulatory liabilities – noncurrent	4,258	4,219
Regulatory liabilities—current	73	65
Total Regulatory Liabilities	4,331	4,284
CECONY | Future income tax
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	2,363	2,390
CECONY | Allowance for cost of removal less salvage
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	790	719
CECONY | TCJA net benefits
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	411	0
CECONY | Energy efficiency portfolio standard unencumbered funds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	122	122
CECONY | Net unbilled revenue deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	117	183
CECONY | Pension and other postretirement benefit deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	40	181
CECONY | Property tax refunds
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	45	44
CECONY | Settlement of prudence proceeding
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	37	66
CECONY | Property tax reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	107
CECONY | Earnings sharing - electric, gas and steam
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	27	19
CECONY | System benefit charge carrying charge
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	24	11
CECONY | Carrying charges on repair allowance and bonus depreciation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	21	42
CECONY | BQDM and REV Demo reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	18	9
CECONY | New York State income tax rate change
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	17	35
CECONY | Settlement of gas proceedings
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	15	27
CECONY | Base rate change deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	21
CECONY | Unrecognized other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	7	92
CECONY | Net utility plant reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1	8
CECONY | Variable-rate tax-exempt debt - cost rate reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1	26
CECONY | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	156	117
CECONY | Revenue decoupling mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	36	21
CECONY | Refundable energy costs
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	8	16
CECONY | Deferred derivative gains
Regulatory Liabilities [Line Items]
Regulatory liabilities—current	$ 29	$ 28

Capitalization - Common Stock (

Capitalization - Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2018	Dec. 31, 2015
Schedule of Capitalization [Line Items]
Value of shares issued		$ 705	$ 343	$ 702
Common Stock
Schedule of Capitalization [Line Items]
Common stock, shares outstanding (in shares)	321,000,000	321,000,000	310,000,000	305,000,000		293,000,000
Shares issued (in shares)		11,000,000	5,000,000	10,000,000
Value of shares issued			$ 1	$ 1
Forward Contract
Schedule of Capitalization [Line Items]
Common stock, shares subject to forward sale agreements (in shares)	5,649,369	5,649,369			14,973,492
Share price (in dollars per share)					$ 75.537
Forward Contract | Common Stock
Schedule of Capitalization [Line Items]
Shares issued (in shares)	9,324,123
Value of shares issued	$ 705
CECONY
Schedule of Capitalization [Line Items]
Common stock, shares outstanding (in shares)	21,976,200	21,976,200
CECONY | Common Stock
Schedule of Capitalization [Line Items]
Common stock, shares outstanding (in shares)	235,000,000	235,000,000	235,000,000	235,000,000		235,000,000

Capitalization - Dividends (Det

Capitalization - Dividends (Details)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Percentage limitation for income available for dividends (not more than)	100.00%
Rolling average calculation of income available for dividends (years)	2 years

Capitalization - Schedule of Lo

Capitalization - Schedule of Long-Term Debt Maturities (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
2,019	$ 650
2,020	866
2,021	1,260
2,022	413
2,023	293
CECONY
Debt Instrument [Line Items]
2,019	475
2,020	350
2,021	640
2,022	0
2,023	$ 0

Capitalization - Long-term Debt

Capitalization - Long-term Debt, Additional Information (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Non-recourse debt		$ 2,076,000,000	$ 915,000,000
Short-term debt		825,000,000	0
Long-term debt		18,145,000,000	16,029,000,000
Transition Bonds Issued in 2004
Debt Instrument [Line Items]
Long-term debt		2,000,000	7,000,000
PG&E Project
Debt Instrument [Line Items]
Long-term debt		1,050,000,000
PG&E Project | Scenario, Forecast
Debt Instrument [Line Items]
Short-term debt	$ 1,050,000,000
CECONY
Debt Instrument [Line Items]
Long-term debt		14,151,000,000	13,265,000,000
CECONY | Tax-Exempt Debt
Debt Instrument [Line Items]
Debt instrument, face amount		450,000,000
Long-term debt		$ 450,000,000	$ 1,086,000,000

Capitalization - Carrying Amoun

Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized debt expense	$ 185	$ 142
Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	18,145	16,029
Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	18,740	18,147
CECONY
Debt Instrument [Line Items]
Unamortized debt discount	139	121
CECONY | Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	14,151	13,625
CECONY | Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	$ 14,685	$ 15,163

Capitalization - Significant De

Capitalization - Significant Debt Covenants (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Maximum ratio of consolidated debt to consolidated total capital	0.53
CECONY
Debt Instrument [Line Items]
Maximum ratio of consolidated debt to consolidated total capital	0.54
Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount	$ 825,000,000
Debt term	2 years
Maximum ratio of consolidated debt to consolidated total capital	0.65
Covenant principal balance amount limit	$ 150,000,000
Term Loan | CECONY
Debt Instrument [Line Items]
Covenant principal balance amount limit	$ 150,000,000
Notes
Debt Instrument [Line Items]
Maximum ratio of consolidated debt to consolidated total capital	0.675
Covenant principal balance amount limit	$ 100,000,000
Notes | CECONY
Debt Instrument [Line Items]
Covenant principal balance amount limit	100,000,000
Tax-Exempt Debt | CECONY
Debt Instrument [Line Items]
Debt instrument, face amount	$ 450,000,000
Maximum ratio of consolidated debt to consolidated total capital	0.65

Short-Term Borrowing (Details)

Short-Term Borrowing (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 1,741,000,000	$ 1,741,000,000	$ 577,000,000
Weighted average interest rate		3.00%	1.80%
Loans outstanding under credit agreement	0	$ 0	$ 0
Letters of credit outstanding	$ 0	$ 0
Maximum ratio of consolidated debt to consolidated total capital	0.53	0.53
Minimum percentage of liens on assets	5.00%	5.00%
Failure to pay, maximum aggregate limit	$ 150,000,000	$ 150,000,000
Term Loan
Short-term Debt [Line Items]
Short-term borrowings	$ 825,000,000	$ 825,000,000
Debt term	6 months
Maximum
Short-term Debt [Line Items]
Maximum ratio of consolidated debt to consolidated total capital	0.65	0.65
Revolving Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 1,500,000,000	$ 1,500,000,000
Current amount available	1,000,000,000	1,000,000,000
Letters of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	1,200,000,000	1,200,000,000
CECONY
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 1,192,000,000	$ 1,192,000,000	$ 150,000,000
Weighted average interest rate		3.00%	1.80%
Maximum ratio of consolidated debt to consolidated total capital	0.54	0.54
CECONY | Revolving Credit
Short-term Debt [Line Items]
Maximum borrowing capacity	$ 2,250,000,000	$ 2,250,000,000

Pension Benefits - Total Period

Pension Benefits - Total Periodic Benefit Costs (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 290	$ 263	$ 275
Interest cost on projected benefit obligation	561	591	596
Expected return on plan assets	(1,033)	(968)	(947)
Recognition of net actuarial loss	688	595	596
Recognition of prior service cost/(credit)	(17)	(17)	4
TOTAL PERIODIC BENEFIT COST	489	464	524
Cost capitalized	(127)	(181)	(214)
Reconciliation to rate level	(92)	(34)	54
Total expense/(credit) recognized	270	249	364
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	272	246	258
Interest cost on projected benefit obligation	525	554	559
Expected return on plan assets	(979)	(917)	(898)
Recognition of net actuarial loss	651	563	565
Recognition of prior service cost/(credit)	(19)	(19)	2
TOTAL PERIODIC BENEFIT COST	450	427	486
Cost capitalized	(119)	(169)	(203)
Reconciliation to rate level	(100)	(41)	58
Total expense/(credit) recognized	$ 231	$ 217	$ 341

Pension Benefits - Schedule of

Pension Benefits - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	$ 330
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	326	$ 330
Pension Benefits
CHANGE IN PROJECTED BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	15,536	14,095	$ 14,377
Service cost – excluding administrative expenses	286	259	271
Interest cost on projected benefit obligation	561	591	596
Net actuarial loss/(gain)	(1,219)	1,231	(302)
Plan amendments	0	6	(256)
Benefits paid	(715)	(646)	(591)
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	14,449	15,536	14,095
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	14,274	12,472	11,759
Actual return on plan assets	(536)	2,041	829
Employer contributions	473	450	508
Benefits paid	(715)	(646)	(591)
Administrative expenses	(46)	(43)	(33)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	13,450	14,274	12,472
FUNDED STATUS	(999)	(1,262)	(1,623)
Unrecognized net loss	2,464	2,760	3,157
Unrecognized prior service costs	(205)	(223)	(244)
Accumulated benefit obligation	13,030	13,897	12,655
CECONY
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	301
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	301	301
CECONY | Pension Benefits
CHANGE IN PROJECTED BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	14,567	13,203	13,482
Service cost – excluding administrative expenses	267	241	254
Interest cost on projected benefit obligation	525	554	559
Net actuarial loss/(gain)	(1,159)	1,171	(282)
Plan amendments	0	0	(259)
Benefits paid	(658)	(602)	(551)
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	13,542	14,567	13,203
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	13,519	11,815	11,141
Actual return on plan assets	(507)	1,935	787
Employer contributions	434	412	469
Benefits paid	(658)	(602)	(551)
Administrative expenses	(44)	(41)	(31)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	12,744	13,519	11,815
FUNDED STATUS	(798)	(1,048)	(1,388)
Unrecognized net loss	2,338	2,624	2,995
Unrecognized prior service costs	(222)	(242)	(258)
Accumulated benefit obligation	$ 12,161	$ 12,972	$ 11,806

Pension Benefits - Additional I

Pension Benefits - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Pension liability	$ 263,000,000
Investments value	326,000,000	$ 330,000,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets and liabilities for future income taxes, net	273,000,000
Charge to OCI	7,000,000
Net loss estimated to be amortized	512,000,000
Prior service cost estimated to be amortized	(17,000,000)
Investments value	13,450,000,000	14,274,000,000	$ 12,472,000,000	$ 11,759,000,000
Accumulated benefit obligation	13,030,000,000	13,897,000,000	12,655,000,000
Defined benefit plan, bond amount (excess of)	50,000,000
Estimated future employer contributions	332,000,000
Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	316,000,000	331,000,000
CECONY
Defined Benefit Plan Disclosure [Line Items]
Pension liability	250,000,000
Investments value	301,000,000	301,000,000
CECONY | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets and liabilities for future income taxes, net	265,000,000
Charge to OCI	1,000,000
Net loss estimated to be amortized	486,000,000
Prior service cost estimated to be amortized	(19,000,000)
Investments value	12,744,000,000	13,519,000,000	11,815,000,000	$ 11,141,000,000
Accumulated benefit obligation	12,161,000,000	12,972,000,000	$ 11,806,000,000
Estimated future employer contributions	301,000,000
CECONY | Other Nonqualified Supplemental Defined Benefit Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 285,000,000	$ 297,000,000

Pension Benefits - Schedule o_2

Pension Benefits - Schedule of Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CECONY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.25%	4.25%	4.25%
Rate of compensation increase	4.25%	4.25%	4.25%
O&R
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.00%	4.00%	4.00%
Rate of compensation increase	4.00%	4.00%	4.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate, benefit obligations	4.25%	3.70%	4.25%
Discount rate, net periodic benefit cost	3.70%	4.25%	4.25%
Expected return on plan assets	7.50%	7.50%	7.80%

Pension Benefits - Schedule o_3

Pension Benefits - Schedule of Expected Benefit Payments (Details) - Pension Benefits $ in Millions	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,019	$ 707
2,020	726
2,021	740
2,022	755
2,023	772
2024-2028	4,072
CECONY
Defined Benefit Plan Disclosure [Line Items]
2,019	658
2,020	676
2,021	689
2,022	703
2,023	718
2024-2028	$ 3,795

Pension Benefits - Schedule o_4

Pension Benefits - Schedule of Plan Assets Allocations (Details) - Pension Benefits	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	100.00%
Plan Assets Percentage	100.00%	100.00%	100.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Percentage	51.00%	58.00%	58.00%
Equity Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	45.00%
Equity Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	55.00%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Percentage	39.00%	33.00%	33.00%
Debt Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	33.00%
Debt Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	43.00%
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Percentage	10.00%	9.00%	9.00%
Real Estate | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	10.00%
Real Estate | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	14.00%

Pension Benefits - Schedule o_5

Pension Benefits - Schedule of Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	$ 326	$ 330
Private Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets		336
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets		1,214
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	(204)	(262)
Funds for retiree health benefits measured at NAV per share	(33)	(36)
Total funds for retiree health benefits	(237)	298
Investments (excluding funds for retiree health benefits)	14,105	14,683
Pending activities	(655)	(409)
Total fair value of plan net assets	13,450	14,274	$ 12,472	$ 11,759
Pension Benefits | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	3,525	3,900
Pension Benefits | International Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	2,896	4,132
Pension Benefits | U.S. Government Issued Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	1,886	1,786
Pension Benefits | Corporate Bonds Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	2,619	2,450
Pension Benefits | Structured Assets Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	6	3
Pension Benefits | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	121	125
Pension Benefits | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	716	476
Pension Benefits | Futures
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	568	308
Pension Benefits | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	12,337	13,180
Pension Benefits | Private Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	440
Pension Benefits | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	1,310
Pension Benefits | Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	255	251
Pension Benefits | Investments Valued Using NAV Per Share
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	2,005	1,801
Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	(118)	(168)
Investments (excluding funds for retiree health benefits)	7,021	8,268
Pension Benefits | Level 1 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	3,515	3,872
Pension Benefits | Level 1 | International Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	2,896	4,132
Pension Benefits | Level 1 | U.S. Government Issued Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Pension Benefits | Level 1 | Corporate Bonds Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Pension Benefits | Level 1 | Structured Assets Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Pension Benefits | Level 1 | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Pension Benefits | Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	160	124
Pension Benefits | Level 1 | Futures
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	568	308
Pension Benefits | Level 1 | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	7,139	8,436
Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	(86)	(94)
Investments (excluding funds for retiree health benefits)	5,112	4,650
Pension Benefits | Level 2 | U.S. Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	10	28
Pension Benefits | Level 2 | U.S. Government Issued Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	1,886	1,786
Pension Benefits | Level 2 | Corporate Bonds Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	2,619	2,450
Pension Benefits | Level 2 | Structured Assets Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	6	3
Pension Benefits | Level 2 | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	121	125
Pension Benefits | Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	556	352
Pension Benefits | Level 2 | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	$ 5,198	$ 4,744

Pension Benefits - Schedule o_6

Pension Benefits - Schedule of Employer Contribution to Defined Savings Plan (Details) - Defined Contribution Savings Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Employer contribution to the defined savings plan	$ 45	$ 40	$ 36
CECONY
Defined Benefit Plan Disclosure [Line Items]
Employer contribution to the defined savings plan	$ 39	$ 35	$ 32

Other Postretirement Benefits -

Other Postretirement Benefits - Net Periodic Postretirement Benefit Costs (Details) - Other Postretirement Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 20	$ 20	$ 18
Interest cost on accumulated other postretirement benefit obligation	42	46	48
Expected return on plan assets	(73)	(69)	(77)
Recognition of net actuarial loss/(gain)	8	2	5
Recognition of prior service cost/(credit)	(6)	(17)	(20)
TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT)	(9)	(18)	(26)
Cost capitalized	(8)	8	11
Reconciliation to rate level	8	(4)	22
Total expense/(credit) recognized	(9)	(14)	7
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost	14	13	13
Interest cost on accumulated other postretirement benefit obligation	34	38	40
Expected return on plan assets	(63)	(61)	(67)
Recognition of net actuarial loss/(gain)	3	(3)	3
Recognition of prior service cost/(credit)	(2)	(11)	(14)
TOTAL PERIODIC POSTRETIREMENT BENEFIT COST/(CREDIT)	(14)	(24)	(25)
Cost capitalized	(6)	10	10
Reconciliation to rate level	9	(2)	22
Total expense/(credit) recognized	$ (11)	$ (16)	$ 7

Other Postretirement Benefits_2

Other Postretirement Benefits - Schedule of Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	$ 330
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	326	$ 330
CECONY
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	301
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	301	301
Other Postretirement Benefits
CHANGE IN BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	1,219	1,198	$ 1,287
Service cost	20	20	18
Interest cost on accumulated other postretirement benefit obligation	42	46	48
Net actuarial loss/(gain)	(70)	53	(57)
Benefits paid and administrative expenses, net of subsidies	(135)	(134)	(134)
Participant contributions	38	36	36
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	1,114	1,219	1,198
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	1,039	975	994
Actual return on plan assets	(66)	150	60
Employer contributions	6	17	7
Employer group waiver plan subsidies	34	34	35
Participant contributions	37	35	36
Benefits paid	(165)	(172)	(157)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	885	1,039	975
FUNDED STATUS	(229)	(180)	(223)
Unrecognized net loss/(gain)	14	(47)	(24)
Unrecognized prior service costs	(8)	(14)	(31)
Other Postretirement Benefits | CECONY
CHANGE IN BENEFIT OBLIGATION
Projected benefit obligation at beginning of year	985	1,007	1,093
Service cost	14	13	13
Interest cost on accumulated other postretirement benefit obligation	34	38	40
Net actuarial loss/(gain)	(32)	16	(52)
Benefits paid and administrative expenses, net of subsidies	(125)	(124)	(122)
Participant contributions	37	35	35
PROJECTED BENEFIT OBLIGATION AT END OF YEAR	913	985	1,007
CHANGE IN PLAN ASSETS
Fair value of plan assets at beginning of year	893	851	870
Actual return on plan assets	(54)	130	52
Employer contributions	6	8	7
Employer group waiver plan subsidies	32	30	33
Participant contributions	37	35	35
Benefits paid	(155)	(161)	(146)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	759	893	851
FUNDED STATUS	(154)	(92)	(156)
Unrecognized net loss/(gain)	(2)	(85)	(42)
Unrecognized prior service costs	$ (5)	$ (7)	$ (18)

Other Postretirement Benefits_3

Other Postretirement Benefits - Additional Information (Details) - Other Postretirement Benefits $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
Increase in liability for other postretirement benefits	$ 49
Increase (decrease) in regulatory liabilities	70
Net losses unrecognized to be amortized	(7)
Prior service cost estimated to be amortized	$ (2)
Health care cost trend rate for net periodic benefit cost, current	5.60%
Health care cost trend rate for net periodic benefit cost	4.50%
Health care cost trend rate for benefit obligations, current	5.40%
Health care cost trend rate for benefit obligations	4.50%
Expected contributions	$ 10
Clean Energy Businesses, Con Edison Transmission and RECO
Defined Benefit Plan Disclosure [Line Items]
Credit to OCI (net of taxes) for unrecognized net losses	4
Debit to OCI (net of taxes) for unrecognized prior service costs	1
CECONY
Defined Benefit Plan Disclosure [Line Items]
Increase in liability for other postretirement benefits	62
Increase (decrease) in regulatory liabilities	(85)
Credit to OCI (net of taxes) for unrecognized net losses	1
Net losses unrecognized to be amortized	(10)
Prior service cost estimated to be amortized	(2)
Expected contributions	$ 8

Other Postretirement Benefits_4

Other Postretirement Benefits - Schedule of Actuarial Assumptions (Details) - Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Expected Return on Plan Assets	7.50%	7.50%	7.00%
CECONY
Defined Benefit Plan Disclosure [Line Items]
Discount Rate, Benefit Obligations	4.15%	3.55%	4.00%
Discount Rate, Net Periodic Benefit Cost	3.55%	4.00%	4.05%
O&R
Defined Benefit Plan Disclosure [Line Items]
Discount Rate, Benefit Obligations	4.30%	3.70%	4.20%
Discount Rate, Net Periodic Benefit Cost	3.70%	4.20%	4.20%

Other Postretirement Benefits_5

Other Postretirement Benefits - Schedule of Change of Assumed Health Care Cost Trend Rate (Details) - Other Postretirement Benefits $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Increase
Effect on accumulated other postretirement benefit obligation	$ 9
Effect on service cost and interest cost components for 2018	2
Decrease
Effect on accumulated other postretirement benefit obligation	11
Effect on service cost and interest cost components for 2018	(1)
CECONY
Increase
Effect on accumulated other postretirement benefit obligation	(18)
Effect on service cost and interest cost components for 2018	(1)
Decrease
Effect on accumulated other postretirement benefit obligation	31
Effect on service cost and interest cost components for 2018	$ 1

Other Postretirement Benefits_6

Other Postretirement Benefits - Schedule of Expected Benefit Payments (Details) - Other Postretirement Benefits $ in Millions	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
2,019	$ 80
2,020	78
2,021	76
2,022	75
2,023	74
2024-2028	359
CECONY
Defined Benefit Plan Disclosure [Line Items]
2,019	70
2,020	67
2,021	65
2,022	64
2,023	63
2024-2028	$ 302

Other Postretirement Benefits_7

Other Postretirement Benefits - Schedule of Plan Assets Allocations (Details) - Other Postretirement Benefits - CECONY	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	100.00%
Plan Assets Percentage	100.00%	100.00%	100.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Percentage	52.00%	60.00%	60.00%
Equity Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	42.00%
Equity Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	80.00%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Plan Assets Percentage	48.00%	40.00%	40.00%
Debt Securities | Minimum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	20.00%
Debt Securities | Maximum
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Range	58.00%

Other Postretirement Benefits_8

Other Postretirement Benefits - Schedule of Fair Values of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	$ 326	$ 330
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	204	262
Investments (including funds for retiree health benefits)	829	984
Funds for retiree health benefits measured at NAV per share	33	36
Pending activities	23	19
Total fair value of plan net assets	885	1,039	$ 975	$ 994
Other Postretirement Benefits | Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	322	420
Other Postretirement Benefits | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	289	286
Other Postretirement Benefits | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	14	16
Other Postretirement Benefits | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	625	722
Other Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	118	168
Investments (including funds for retiree health benefits)	118	168
Other Postretirement Benefits | Level 1 | Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Other Postretirement Benefits | Level 1 | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Other Postretirement Benefits | Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Other Postretirement Benefits | Level 1 | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	0	0
Other Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Funds for retiree health benefits	86	94
Investments (including funds for retiree health benefits)	711	816
Other Postretirement Benefits | Level 2 | Equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	322	420
Other Postretirement Benefits | Level 2 | Other Fixed Income Debt
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	289	286
Other Postretirement Benefits | Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	14	16
Other Postretirement Benefits | Level 2 | Total investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan net assets	$ 625	$ 722

Environmental Matters - Accrued

Environmental Matters - Accrued Liabilities and Regulatory Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Site Contingency [Line Items]
Accrued Liabilities	$ 779	$ 737
Regulatory assets	4,370	4,333
Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	689	651
Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	90	86
Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	779	737
Regulatory assets	810	793
CECONY
Site Contingency [Line Items]
Accrued Liabilities	693	637
Regulatory assets	3,987	3,925
CECONY | Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	603	551
CECONY | Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	90	86
CECONY | Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	693	637
Regulatory assets	$ 716	$ 677

Environmental Matters - Environ

Environmental Matters - Environmental Remediation Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 25	$ 24
CECONY
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 18	$ 19

Environmental Matters - Additio

Environmental Matters - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Asbestos Proceedings
Site Contingency [Line Items]
Estimated undiscounted asbestos liability (years)	15 years
CECONY | Asbestos Proceedings
Site Contingency [Line Items]
Estimated undiscounted asbestos liability (years)	15 years
Superfund Sites
Site Contingency [Line Items]
Remediation cost estimate	$ 28
Superfund Sites | Manufactured Gas Plant Sites | Maximum
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)	2,800
Superfund Sites | CECONY
Site Contingency [Line Items]
Remediation cost estimate	21
Superfund Sites | CECONY | Manufactured Gas Plant Sites | Maximum
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)	$ 2,600

Environmental Matters - Accru_2

Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Site Contingency [Line Items]
Regulatory assets	$ 4,370	$ 4,333
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers' Compensation
Site Contingency [Line Items]
Accrued liability	79	84
Regulatory assets	5	10
CECONY
Site Contingency [Line Items]
Regulatory assets	3,987	3,925
CECONY | Asbestos Suits
Site Contingency [Line Items]
Accrued liability	7	7
Regulatory assets	7	7
CECONY | Workers' Compensation
Site Contingency [Line Items]
Accrued liability	75	80
Regulatory assets	$ 5	$ 10

Other Material Contingencies -

Other Material Contingencies - Manhattan Explosion and Fire (Details) $ in Millions	Mar. 12, 2014buildingpeople	Feb. 28, 2017USD ($)	Dec. 31, 2018USD ($)lawsuit	Dec. 31, 2017USD ($)
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 4,641	$ 4,577
Settlement of gas proceedings
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 15	$ 27
Manhattan Explosion and Fire
Loss Contingencies [Line Items]
Number of buildings destroyed by fire | building	2
Number of people died in explosion and fire incident | people	8
Number of people injured in explosion and fire incident (more than) | people	50
Amount of costs that will not recover from customers		$ 126
Number of pending lawsuits | lawsuit			80
Manhattan Explosion and Fire | Settlement of gas proceedings
Loss Contingencies [Line Items]
Accrued regulatory liability		$ 27

Other Material Contingencies _2

Other Material Contingencies - Manhattan Steam Main Rupture (Details) $ in Millions	Dec. 31, 2018USD ($)
Property, Damage, Clean Up and Other Costs Related With Manhattan Steam Main Rupture
Loss Contingencies [Line Items]
Loss contingency	$ 14
Capital, Retirement and Other Costs Related with Manhattan Steam Main Rupture
Loss Contingencies [Line Items]
Loss contingency	$ 8

Other Material Contingencies _3

Other Material Contingencies - Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Guarantee obligations maximum exposure	$ 2,439	$ 2,073

Other Material Contingencies _4

Other Material Contingencies - Total Guarantees (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 2,439	$ 2,073
Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	1,146
Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	683
Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	540
Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	70
0 – 3 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	1,411
0 – 3 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	742
0 – 3 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	462
0 – 3 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	137
0 – 3 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	70
4 – 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	424
4 – 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	404
4 – 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	20
4 – 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
4 – 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
Greater than 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	604
Greater than 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
Greater than 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	201
Greater than 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	403
Greater than 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 0

Other Material Contingencies _5

Other Material Contingencies - Con Edison Transmission (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2014
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,439	$ 2,073
Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Guarantor Obligations [Line Items]
Estimated project cost percentage	175.00%
Financial Guarantee in Behalf of CET Gas for Proposed Gas Transmission Project
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 124
NY Transco | Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Guarantor Obligations [Line Items]
Ownership interest, percentage			45.70%

Other Material Contingencies _6

Other Material Contingencies - Other (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,439	$ 2,073
Financial Guarantee for Indemnity Agreements for Surety Bonds in Connection with Operation of Solar Energy Facilities and Energy Service Projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 70

Electricity Purchase Agreemen_3

Electricity Purchase Agreements - Summary of Estimated Capacity and Other Fixed Payments (Details) $ in Millions	Dec. 31, 2018USD ($)
Long-term Contract for Purchase of Electric Power [Line Items]
2,019	$ 206
2,020	117
2,021	65
2,022	54
2,023	55
All Years Thereafter	601
CECONY
Long-term Contract for Purchase of Electric Power [Line Items]
2,019	202
2,020	113
2,021	64
2,022	54
2,023	55
All Years Thereafter	$ 601

Electricity Purchase Agreemen_4

Electricity Purchase Agreements - Summary of Capacity, Energy and Other Fixed Payments (Details) - CECONY - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	$ 318	$ 552	$ 692
Indian Point
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	6	211	203
Linden Cogeneration
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	0	114	304
Astoria Energy
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	0	0	50
Astoria Generating Company
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	179	92	16
Brooklyn Navy Yard
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	124	117	119
Cogen Technologies
Long-term Contract for Purchase of Electric Power [Line Items]
Capacity, energy and other fixed payments	$ 9	$ 18	$ 0

Leases - Schedule of Capital Le

Leases - Schedule of Capital Leases (Details) - Common - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Property Subject to or Available for Operating Lease [Line Items]
Utility Plant	$ 1	$ 2
CECONY
Property Subject to or Available for Operating Lease [Line Items]
Utility Plant	$ 1	$ 1

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Leased Assets [Line Items]
Accumulated amortization	$ 4	$ 3
CECONY
Operating Leased Assets [Line Items]
Accumulated amortization	$ 2	$ 2
Increase in annual payments, percentage	2.18%
Decrease in transformer installations, percentage	0.50%

Leases - Future Minimum Rental

Leases - Future Minimum Rental Payments for Operating Leases (Details) $ in Millions	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
2,019	$ 72
2,020	72
2,021	71
2,022	68
2,023	68
All years thereafter	890
Total	1,241
CECONY
Operating Leased Assets [Line Items]
2,019	56
2,020	56
2,021	54
2,022	53
2,023	53
All years thereafter	592
Total	$ 864

Goodwill (Details)

Goodwill (Details)	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2016USD ($)business_acquisition	Dec. 31, 2017USD ($)
Goodwill [Line Items]
Goodwill	$ 440,000,000		$ 428,000,000
Impairment charge	0
CECONY
Goodwill [Line Items]
Goodwill	245,000,000		245,000,000
O&R
Goodwill [Line Items]
Goodwill	161,000,000		161,000,000
O&R Merger
Goodwill [Line Items]
Goodwill	406,000,000		406,000,000
Gas Storage Company | CET Gas
Goodwill [Line Items]
Goodwill	8,000,000		8,000,000
Energy Services Company | Clean Energy Businesses
Goodwill [Line Items]
Goodwill		$ 15,000,000
Number of businesses acquired included in goodwill impairment test | business_acquisition		2
Impairment charge		$ 15,000,000
Impairment charge, net of tax		$ 12,000,000
Residential Solar Company | Clean Energy Businesses
Goodwill [Line Items]
Goodwill	14,000,000		$ 14,000,000
Battery Storage Company [Member] | Clean Energy Businesses
Goodwill [Line Items]
Goodwill	$ 12,000,000

Income Tax - Schedule of Compon

Income Tax - Schedule of Components of Income Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
State
Current	$ (10)	$ (2)	$ (42)
Deferred	107	103	188
Federal
Current	3	(11)	(43)
Deferred	310	391	604
Amortization of investment tax credits	(9)	(9)	(9)
Total income tax expense	401	472	698
CECONY
State
Current	6	37	(1)
Deferred	82	75	114
Federal
Current	(34)	73	59
Deferred	275	504	435
Amortization of investment tax credits	(3)	(4)	(4)
Total income tax expense	$ 326	$ 685	$ 603

Income Tax - Schedule of Differ

Income Tax - Schedule of Differences on Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Property basis differences	$ 7,402	$ 6,555
Regulatory assets:
Unrecognized pension and other postretirement costs	627	697
Environmental remediation costs	227	219
Deferred storm costs	21	11
Other regulatory assets	273	269
Equity investments	102	263
Total deferred tax liabilities	8,652	8,014
Deferred tax assets:
Accrued pension and other postretirement costs	248	264
Future income tax	702	698
Other regulatory liabilities	632	593
Superfund and other environmental costs	218	203
Asset retirement obligations	114	86
Loss carryforwards	229	95
Tax credits carryforward	817	658
Valuation allowance	(33)	(33)
Other	53	112
Total deferred tax assets	2,980	2,676
Net deferred tax liabilities	5,672	5,338
Unamortized investment tax credits	148	157
Net deferred tax liabilities and unamortized investment tax credits	5,820	5,495
CECONY
Deferred tax liabilities:
Property basis differences	6,446	5,968
Regulatory assets:
Unrecognized pension and other postretirement costs	591	656
Environmental remediation costs	200	187
Deferred storm costs	0	0
Other regulatory assets	252	241
Equity investments	0	0
Total deferred tax liabilities	7,489	7,052
Deferred tax assets:
Accrued pension and other postretirement costs	180	187
Future income tax	662	660
Other regulatory liabilities	554	524
Superfund and other environmental costs	194	176
Asset retirement obligations	82	79
Loss carryforwards	0	0
Tax credits carryforward	0	0
Valuation allowance	0	0
Other	102	148
Total deferred tax assets	1,774	1,774
Net deferred tax liabilities	5,715	5,278
Unamortized investment tax credits	24	28
Net deferred tax liabilities and unamortized investment tax credits	$ 5,739	$ 5,306

Income Tax - Additional Informa

Income Tax - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Decrease in net deferred tax liabilities resulting from TCJA		$ 13,000,000	$ 5,312,000,000
Change in net income resulting from TCJA			259,000,000
Deferred tax asset, valuation allowance	$ 33,000,000	33,000,000	33,000,000
Decrease in uncertain tax positions resulting from settlement of claims filed in previous years		3,000,000	6,000,000	$ 0
Effective income tax rate reconciliation, uncertainty of taxes		4,000,000
Penalties for uncertain tax positions		0	0	0
Amount of interest and penalties in their consolidated balance sheets	0		0
Unrecognized tax benefits that would have an impact on effective tax rate		6,000,000
New York State
Operating Loss Carryforwards [Line Items]
Decrease in effective tax rate resulting from tax settlement			6,000,000
Charitable Contribution
Operating Loss Carryforwards [Line Items]
Deferred tax asset, valuation allowance		0
General Business Tax Credit
Operating Loss Carryforwards [Line Items]
Tax credit carryovers		817,000,000
Expiring in 2020
Operating Loss Carryforwards [Line Items]
Charitable contribution carryforwards					$ 5,000,000
Expiring in 2021
Operating Loss Carryforwards [Line Items]
Charitable contribution carryforwards				5,000,000
Expiring in 2022
Operating Loss Carryforwards [Line Items]
Charitable contribution carryforwards	7,000,000		7,000,000
Expiring in 2023
Operating Loss Carryforwards [Line Items]
Charitable contribution carryforwards		5,000,000
Federal
Operating Loss Carryforwards [Line Items]
Additional depreciation deducted			477,000,000
Operating loss carryforwards	563,000,000	711,000,000	563,000,000
Operating loss carryover subject to expiration	520,000,000		520,000,000
Operating loss carryover not subject to expiration		191,000,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, valuation allowance		21,000,000
State | New York State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	97,000,000	398,000,000	97,000,000
Operating loss carryforwards, valuation allowance		12,000,000
Decrease in uncertain tax positions resulting from settlement of claims filed in previous years			9,000,000
State | Carry Back to 2015 | New York State
Operating Loss Carryforwards [Line Items]
Income tax recovery resulting from operating loss carry back			9,000,000
State | Carry Back to 2015 and 2016 | New York State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		99,000,000
Income tax recovery resulting from operating loss carry back		9,000,000
State | Carried Forward to Future Years | New York State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		299,000,000
Parent Company
Operating Loss Carryforwards [Line Items]
Change in net income resulting from TCJA		42,000,000	(21,000,000)
Clean Energy Businesses
Operating Loss Carryforwards [Line Items]
Change in net income resulting from TCJA			269,000,000
Con Edison Transmission
Operating Loss Carryforwards [Line Items]
Change in net income resulting from TCJA			11,000,000
Future Income Tax
Operating Loss Carryforwards [Line Items]
Increase in regulatory liability resulting from TCJA		54,000,000	3,713,000,000
Accelerated Tax Depreciation Benefits
Operating Loss Carryforwards [Line Items]
Increase in regulatory liability resulting from TCJA			2,684,000,000
Future Income Tax
Operating Loss Carryforwards [Line Items]
Decrease in regulatory asset resulting from TCJA			1,250,000,000
Revenue Taxes
Operating Loss Carryforwards [Line Items]
Decrease in regulatory asset resulting from TCJA			90,000,000
CECONY
Operating Loss Carryforwards [Line Items]
Decrease in net deferred tax liabilities resulting from TCJA		50,000,000	4,781,000,000
Deferred tax asset, valuation allowance	0	0	0
Decrease in uncertain tax positions resulting from settlement of claims filed in previous years		3,000,000	0	$ 0
Effective income tax rate reconciliation, uncertainty of taxes		2,000,000
Unrecognized tax benefits that would have an impact on effective tax rate		4,000,000
CECONY | New York State
Operating Loss Carryforwards [Line Items]
Decrease in uncertain tax positions resulting from settlement of claims filed in previous years			4,000,000
Decrease in effective tax rate resulting from tax settlement			1,000,000
CECONY | Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	153,000,000		153,000,000
CECONY | Future Income Tax
Operating Loss Carryforwards [Line Items]
Increase in regulatory liability resulting from TCJA	$ 3,513,000,000	49,000,000	3,513,000,000
CECONY | Accelerated Tax Depreciation Benefits
Operating Loss Carryforwards [Line Items]
Increase in regulatory liability resulting from TCJA		2,593,000,000	2,542,000,000
CECONY | Future Income Tax
Operating Loss Carryforwards [Line Items]
Decrease in regulatory asset resulting from TCJA			1,182,000,000
CECONY | Revenue Taxes
Operating Loss Carryforwards [Line Items]
Decrease in regulatory asset resulting from TCJA		$ 1,000,000	$ 86,000,000

Income Tax - Schedule of Income

Income Tax - Schedule of Income Tax Reconciliation (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
STATUTORY TAX RATE
Federal	21.00%	35.00%	35.00%
Changes in computed taxes resulting from:
State income tax	4.00%	4.00%	4.00%
Cost of removal	1.00%	1.00%	(1.00%)
Other plant-related items	(1.00%)	(1.00%)	0.00%
TCJA deferred tax re-measurement	2.00%	(13.00%)	0.00%
Amortization of excess deferred federal income taxes	(3.00%)	(0.00%)	(0.00%)
Renewable energy credits	(1.00%)	(1.00%)	(1.00%)
Research and development credits	(0.00%)	(0.00%)	(1.00%)
Other	0.00%	(2.00%)	0.00%
Effective tax rate	23.00%	23.00%	36.00%
CECONY
STATUTORY TAX RATE
Federal	21.00%	35.00%	35.00%
Changes in computed taxes resulting from:
State income tax	5.00%	4.00%	4.00%
Cost of removal	1.00%	1.00%	(1.00%)
Other plant-related items	(1.00%)	(1.00%)	(1.00%)
TCJA deferred tax re-measurement	0.00%	0.00%	0.00%
Amortization of excess deferred federal income taxes	(3.00%)	(0.00%)	(0.00%)
Renewable energy credits	(0.00%)	(0.00%)	(0.00%)
Research and development credits	(1.00%)	(0.00%)	(1.00%)
Other	(1.00%)	(1.00%)	0.00%
Effective tax rate	21.00%	38.00%	36.00%

Income Tax - Summary of Unrecog

Income Tax - Summary of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 12	$ 42	$ 34
Additions based on tax positions related to the current year	2	1	2
Additions based on tax positions of prior years	1	1	19
Reductions for tax positions of prior years	(2)	(24)	(13)
Reductions from expiration of statute of limitations	(4)	(2)	0
Settlements	(3)	(6)	0
Balance at end of period	6	12	42
CECONY
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	5	21	2
Additions based on tax positions related to the current year	2	1	2
Additions based on tax positions of prior years	1	1	19
Reductions for tax positions of prior years	(1)	(18)	(2)
Reductions from expiration of statute of limitations	0	0	0
Settlements	(3)	0	0
Balance at end of period	$ 4	$ 5	$ 21

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit realized from stock options exercised	$ 4,000,000	$ 25,000,000	$ 20,000,000
Maximum employer contribution match (up to)	1
Amount employee contribution for employer match	9
Maximum employee investment per year (up to)	$ 25,000
Maximum percentage allowed to invest (not more than)	20.00%
CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit realized from stock options exercised	$ 4,000,000	22,000,000	18,000,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)	3 years
Income tax benefit realized from stock options exercised			1,000,000
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period (years)	10 years
Performance RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock received upon vesting (in shares)	1
Compensation expense to be recognized	$ 21,000,000
Nonvested awards, compensation cost not yet recognized, period for recognition (years)	1 year
Payment for settlement of vested units	$ 29,000,000	22,000,000	21,000,000
Performance RSUs | CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense to be recognized	$ 18,000,000
Nonvested awards, compensation cost not yet recognized, period for recognition (years)	1 year
Payment for settlement of vested units	$ 28,000,000	21,000,000	20,000,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)	3 years
Time-based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense to be recognized	$ 2,000,000
Nonvested awards, compensation cost not yet recognized, period for recognition (years)	1 year
Payment for settlement of vested units	$ 1,000,000	1,000,000	1,000,000
Weighted average grant date price per share (in dollars per share)	$ 77.94
Time-based Awards | CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense to be recognized	$ 2,000,000
Nonvested awards, compensation cost not yet recognized, period for recognition (years)	1 year
Payment for settlement of vested units	$ 1,000,000	$ 1,000,000	$ 1,000,000
Weighted average grant date price per share (in dollars per share)	$ 77.94
2013 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock that can be awarded under the plan	5,000,000
TSR Portion | Performance RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Adjustment percentage used for Performance awards	50.00%
Factor used for adjustment of Performance awards, low end (percent)	0.00%
Factor used for adjustment of Performance awards, high end (percent)	200.00%
Weighted average grant date price per share (in dollars per share)	$ 67.26
TSR Portion | Performance RSUs | CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date price per share (in dollars per share)	$ 66.79
Non-TSR Portion | Performance RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Adjustment percentage used for Performance awards	50.00%
Factor used for adjustment of Performance awards, low end (percent)	0.00%
Factor used for adjustment of Performance awards, high end (percent)	200.00%
Weighted average grant date price per share (in dollars per share)	$ 76.37
Non-TSR Portion | Performance RSUs | CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date price per share (in dollars per share)	$ 76.48
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units issued (in shares)	33,100
Weighted average grant date price per share (in dollars per share)	$ 76.08
Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased on the open market	786,385	719,125	720,268
Weighted average share price per share, on shares purchased on open market (in dollars per share)	$ 78.27	$ 79.57	$ 72.67

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 14	$ 63	$ 50
Income tax benefit	4	25	20
Performance-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3	53	42
Time-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2	2	2
Non-employee director deferred stock compensation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3	2	2
Stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	6	6	4
CECONY
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	13	55	44
Income tax benefit	4	22	18
CECONY | Performance-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3	45	36
CECONY | Time-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1	2	2
CECONY | Non-employee director deferred stock compensation
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3	2	2
CECONY | Stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 6	$ 6	$ 4

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used to Calculate Fair Value (Details) - Performance RSUs	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	2.48%	1.76%	0.85%
Risk-free interest rate, maximum	2.63%	1.89%	1.20%
Expected term (years)	3 years	3 years	3 years
Expected share price volatility, minimum (percent)	14.76%	11.01%	17.72%
Expected share price volatility, maximum (percent)	17.71%	14.70%	18.22%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Changes in Status of Performance RSUs' (Details) - Performance RSUs	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Units
Non-vested at beginning of period (in shares) | shares	1,028,932
Granted (in shares) | shares	328,850
Vested (in shares) | shares	(327,069)
Forfeited (in shares) | shares	(24,877)
Transferred (in shares) | shares	0
Non-vested at end of period (in shares) | shares	1,005,836
CECONY
Units
Non-vested at beginning of period (in shares) | shares	784,166
Granted (in shares) | shares	247,532
Vested (in shares) | shares	(261,167)
Forfeited (in shares) | shares	(20,877)
Transferred (in shares) | shares	12,252
Non-vested at end of period (in shares) | shares	761,906
TSR Portion
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 71.74
Granted (in dollars per share)	67.26
Vested (in dollars per share)	57.77
Forfeited (in dollars per share)	72.22
Transferred (in dollars per share)	0
Non-vested at end of period (in dollars per share)	$ 74.81
Adjustment percentage used for Performance awards	50.00%
TSR Portion | CECONY
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 71.06
Granted (in dollars per share)	66.79
Vested (in dollars per share)	57.37
Forfeited (in dollars per share)	71.76
Transferred (in dollars per share)	78.47
Non-vested at end of period (in dollars per share)	74.47
Non-TSR Portion
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	70.11
Granted (in dollars per share)	76.37
Vested (in dollars per share)	63.27
Forfeited (in dollars per share)	74.97
Transferred (in dollars per share)	0
Non-vested at end of period (in dollars per share)	$ 74.27
Adjustment percentage used for Performance awards	0.00%
Non-TSR Portion | CECONY
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)	$ 70.08
Granted (in dollars per share)	76.48
Vested (in dollars per share)	63.18
Forfeited (in dollars per share)	75.14
Transferred (in dollars per share)	72.71
Non-vested at end of period (in dollars per share)	$ 74.42

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Changes in Status of Time-Based Awards (Details) - Time-based Awards	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Units
Non-vested at beginning of period (in shares) | shares	64,870
Granted (in shares) | shares	23,000
Vested (in shares) | shares	(20,523)
Forfeited (in shares) | shares	(2,167)
Non-vested at end of period (in shares) | shares	65,180
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share) | $ / shares	$ 71.93
Granted (in dollars per share) | $ / shares	77.94
Vested (in dollars per share) | $ / shares	61.03
Forfeited (in dollars per share) | $ / shares	73.93
Non-vested at end of period (in dollars per share) | $ / shares	$ 77.42
CECONY
Units
Non-vested at beginning of period (in shares) | shares	61,420
Granted (in shares) | shares	21,400
Vested (in shares) | shares	(19,473)
Forfeited (in shares) | shares	(1,967)
Non-vested at end of period (in shares) | shares	61,380
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share) | $ / shares	$ 71.93
Granted (in dollars per share) | $ / shares	77.94
Vested (in dollars per share) | $ / shares	61.03
Forfeited (in dollars per share) | $ / shares	73.97
Non-vested at end of period (in dollars per share) | $ / shares	$ 77.42

Financial Information by Busi_3

Financial Information by Business Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 12,337	$ 12,033	$ 12,075
Depreciation and amortization	1,438	1,341	1,216
Operating income	2,664	2,774	2,780
Other Income (deductions)	(62)	(48)	(141)
Interest charges	819	729	696
Income taxes on operating income	406	459	714
Total assets	53,920	48,111	48,255
Capital expenditures	5,249	3,606	5,235
Income taxes on non-operating income	(5)	13	(16)
Federal income tax expense		259
Parent Company
Segment Reporting Information [Line Items]
Interest charges	59	50	41
Total assets	19,542	17,231
Federal income tax expense		(21)
Clean Energy Businesses
Segment Reporting Information [Line Items]
Federal income tax expense		269
Con Edison Transmission
Segment Reporting Information [Line Items]
Federal income tax expense		11
CECONY
Segment Reporting Information [Line Items]
Revenues	10,680	10,468	10,165
Depreciation and amortization	1,276	1,195	1,106
Operating income	2,354	2,549	2,451
Other Income (deductions)	(143)	(137)	(189)
Interest charges	689	623	603
Total assets	43,108	40,451
Income taxes on non-operating income	(2)	(3)	(14)
Operating segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Revenues	763	694	1,091
Depreciation and amortization	85	74	42
Operating income	194	69	183
Other Income (deductions)	33	33	21
Interest charges	63	43	34
Income taxes on operating income	19	(273)	53
Total assets	5,821	2,735	2,551
Capital expenditures	1,791	447	1,235
Operating segment | Con Edison Transmission
Segment Reporting Information [Line Items]
Revenues	4	2	0
Depreciation and amortization	1	1	0
Operating income	(7)	(8)	(3)
Other Income (deductions)	91	80	43
Interest charges	20	16	6
Income taxes on operating income	(1)	(11)	0
Total assets	1,425	1,222	1,150
Capital expenditures	248	66	1,078
Operating segment | CECONY
Segment Reporting Information [Line Items]
Revenues	10,680	10,468	10,165
Depreciation and amortization	1,276	1,195	1,106
Operating income	2,354	2,549	2,451
Other Income (deductions)	(143)	(137)	(189)
Interest charges	689	623	603
Income taxes on operating income	328	688	617
Total assets	43,108	40,451	40,856
Capital expenditures	3,005	2,904	2,756
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Revenues	7,971	7,972	8,106
Depreciation and amortization	984	925	865
Operating income	1,799	1,974	1,996
Other Income (deductions)	(110)	(105)	(147)
Interest charges	519	472	459
Income taxes on operating income	233	511	495
Total assets	31,012	29,661	30,708
Capital expenditures	1,861	1,905	1,819
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Revenues	2,078	1,901	1,508
Depreciation and amortization	205	185	159
Operating income	478	495	387
Other Income (deductions)	(23)	(23)	(31)
Interest charges	131	113	105
Income taxes on operating income	87	152	92
Total assets	9,710	8,387	7,553
Capital expenditures	1,050	909	811
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Revenues	631	595	551
Depreciation and amortization	87	85	82
Operating income	77	80	68
Other Income (deductions)	(10)	(9)	(11)
Interest charges	39	38	39
Income taxes on operating income	8	25	30
Total assets	2,386	2,403	2,595
Capital expenditures	94	90	126
Operating segment | O&R
Segment Reporting Information [Line Items]
Revenues	891	874	821
Depreciation and amortization	77	71	67
Operating income	132	161	146
Other Income (deductions)	(19)	(19)	(15)
Interest charges	39	36	36
Income taxes on operating income	21	42	40
Total assets	2,892	2,773	2,758
Capital expenditures	205	189	166
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Revenues	642	642	637
Depreciation and amortization	56	51	49
Operating income	93	115	107
Other Income (deductions)	(14)	(14)	(11)
Interest charges	25	24	24
Income taxes on operating income	14	30	30
Total assets	2,036	1,949	1,949
Capital expenditures	138	128	114
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Revenues	249	232	184
Depreciation and amortization	21	20	18
Operating income	39	46	39
Other Income (deductions)	(5)	(5)	(4)
Interest charges	14	12	12
Income taxes on operating income	7	12	10
Total assets	856	824	809
Capital expenditures	67	61	52
Other
Segment Reporting Information [Line Items]
Revenues	(1)	(5)	(2)
Depreciation and amortization	(1)	0	1
Operating income	(9)	3	3
Other Income (deductions)	(24)	(5)	(1)
Interest charges	8	11	17
Income taxes on operating income	39	13	4
Total assets	674	930	940
Capital expenditures	0	0	0
Other | O&R
Segment Reporting Information [Line Items]
Revenues	0	0	0
Depreciation and amortization	0	0	0
Operating income	0	0	0
Other Income (deductions)	0	0	0
Interest charges	0	0	0
Income taxes on operating income	0	0	0
Total assets	0	0	0
Capital expenditures	0	0	0
Inter-segment
Segment Reporting Information [Line Items]
Revenues	0	0	(7)
Inter-segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Revenues	0	0	7
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Revenues	(98)	(97)	(111)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Revenues	16	16	17
Inter-segment | CECONY | Gas
Segment Reporting Information [Line Items]
Revenues	7	6	6
Inter-segment | CECONY | Steam
Segment Reporting Information [Line Items]
Revenues	$ 75	$ 75	$ 88

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Fair Values of Commodity Derivatives Including Offsetting of Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Net fair value derivative assets/(liabilities)
Gross Amounts of Recognized Assets/ (Liabilities)	$ (23)	$ (17)
Gross Amounts Offset	(1)	0
Net Amounts of Assets/ (Liabilities)	(24)	(17)
Margin deposits	7	12
Interest Rate Swap
Fair value of derivative assets
Net Amounts of Assets/ (Liabilities)	2
Fair value of derivative liabilities
Net Amounts of Assets/ (Liabilities)	(6)
CECONY
Net fair value derivative assets/(liabilities)
Gross Amounts of Recognized Assets/ (Liabilities)	(7)	(14)
Gross Amounts Offset	1	(1)
Net Amounts of Assets/ (Liabilities)	(6)	(15)
Margin deposits	6	11
Fair Value of Derivative Liabilities, Current
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(61)	(67)
Gross Amounts Offset	11	50
Net Amounts of Assets/ (Liabilities)	(50)	(17)
Fair Value of Derivative Liabilities, Current | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(31)	(26)
Gross Amounts Offset	6	14
Net Amounts of Assets/ (Liabilities)	(25)	(12)
Fair Value of Derivative Liabilities, Non-current
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(19)	(43)
Gross Amounts Offset	9	5
Net Amounts of Assets/ (Liabilities)	(10)	(38)
Fair Value of Derivative Liabilities, Non-current | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(12)	(36)
Gross Amounts Offset	6	4
Net Amounts of Assets/ (Liabilities)	(6)	(32)
Fair Value of Derivative Liabilities
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(80)	(110)
Gross Amounts Offset	20	55
Net Amounts of Assets/ (Liabilities)	(60)	(55)
Fair Value of Derivative Liabilities | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(43)	(62)
Gross Amounts Offset	12	18
Net Amounts of Assets/ (Liabilities)	(31)	(44)
Fair Value of Derivative Assets, Current
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	43	83
Gross Amounts Offset	(14)	(51)
Net Amounts of Assets/ (Liabilities)	29	32
Fair Value of Derivative Assets, Current | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	25	39
Gross Amounts Offset	(6)	(15)
Net Amounts of Assets/ (Liabilities)	19	24
Fair Value of Derivative Assets, Non-current
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	14	10
Gross Amounts Offset	(7)	(4)
Net Amounts of Assets/ (Liabilities)	7	6
Fair Value of Derivative Assets, Non-current | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	11	9
Gross Amounts Offset	(5)	(4)
Net Amounts of Assets/ (Liabilities)	6	5
Fair Value of Derivative Assets
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	57	93
Gross Amounts Offset	(21)	(55)
Net Amounts of Assets/ (Liabilities)	36	38
Fair Value of Derivative Assets | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	36	48
Gross Amounts Offset	(11)	(19)
Net Amounts of Assets/ (Liabilities)	$ 25	$ 29

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Realized and Unrealized Gains or Losses on Commodity Derivatives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ 3	$ 3
Total deferred gains/(losses)	5	(99)
Net deferred gains/(losses)	8	(96)
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	8
Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(2)	3
Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	4	5
Non-utility operating revenue
Pre-tax gain/(loss) recognized in income
Unrealized gain/(loss) on derivatives	(5)	0
Other operations and maintenance expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(2)	0
Unrealized gain/(loss) on derivatives	(2)
Deferred Derivative Gains,Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(1)	3
Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	4	0
Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	4	51
Recoverable Energy Costs, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(26)	(154)
Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	27	4
CECONY
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	4	4
Total deferred gains/(losses)	8	(90)
Net deferred gains/(losses)	12	(86)
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(2)	0
CECONY | Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Other operations and maintenance expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(2)	0
CECONY | Deferred Derivative Gains,Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	1	4
CECONY | Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	3	0
CECONY | Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	8	49
CECONY | Recoverable Energy Costs, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(26)	(144)
CECONY | Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ 26	$ 5

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details) gal in Thousands	Dec. 31, 2018MWgalMMBTUMWh
Electric Energy
Derivatives, Fair Value [Line Items]
Notional amount | MWh	28,303,678
Capacity
Derivatives, Fair Value [Line Items]
Notional amount | MW	18,519
Natural Gas
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	164,668,697
Refined Fuels
Derivatives, Fair Value [Line Items]
Notional amount | gal	3,780
CECONY | Electric Energy
Derivatives, Fair Value [Line Items]
Notional amount | MWh	25,458,600
CECONY | Capacity
Derivatives, Fair Value [Line Items]
Notional amount | MW	10,350
CECONY | Natural Gas
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	151,280,000
CECONY | Refined Fuels
Derivatives, Fair Value [Line Items]
Notional amount | gal	3,780

Derivative Instruments and He_6

Derivative Instruments and Hedging Activities - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 106
Makeup of net credit exposure with investment-grade counterparties	28
Makeup of net credit exposure independent system operators	31
Makeup of net credit exposure with commodity exchange brokers	19
Makeup of net credit exposure non-investment grade/non-rated counterparties	28
Interest Rate Swap
Investment Holdings [Line Items]
Derivative liability	6
Derivative asset	2
CECONY
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	13
Makeup of net credit exposure with investment-grade counterparties	7
Makeup of net credit exposure with commodity exchange brokers	6
Clean Energy Businesses | Sempra Energy | Interest Rate Swap
Investment Holdings [Line Items]
Derivative liability	5
Clean Energy Businesses | Coram | Interest Rate Swap
Investment Holdings [Line Items]
Derivative, fixed interest rate			2.0855%
Derivative liability		$ 0
Derivative asset	$ 1

Derivative Instruments and He_7

Derivative Instruments and Hedging Activities - Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features (Details) $ in Millions	Dec. 31, 2018USD ($)
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	$ 36
Collateral posted	6
Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	6
Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	66
Derivatives in net asset position additional collateral	20
Additional Collateral Required Due To Loss Of Unsecured Credit
Derivatives, Fair Value [Line Items]
Collateral posted	1
CECONY
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	24
Collateral posted	0
CECONY | Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	2
CECONY | Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	$ 37

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer out of level 3	$ (2)	$ 11
CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfer out of level 3	(2)	10
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(13)
Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(2)
Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities transferred from Level 3 to Level 2	2
Transfer out of level 3		11
Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities transferred from Level 3 to Level 2	2
Transfer out of level 3		10
Interest Rate Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2
Derivative liabilities	6
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	446	453
Derivative liabilities	66	55
Recurring | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	407	414
Recurring | Netting Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(6)	(39)
Derivative liabilities	(11)	(52)
Recurring | Netting Adjustment | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(1)	(7)
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	293	288
Derivative liabilities	8	8
Recurring | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	270	263
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	152	197
Derivative liabilities	49	93
Recurring | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	137	154
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	7	7
Derivative liabilities	20	6
Recurring | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1	4
Recurring | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	43	50
Derivative liabilities	60	55
Recurring | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	31	40
Derivative liabilities	32	44
Recurring | Commodity | Netting Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(6)	(39)
Derivative liabilities	(11)	(52)
Recurring | Commodity | Netting Adjustment | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(1)	(7)
Derivative liabilities	(6)	(18)
Recurring | Commodity | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	5
Derivative liabilities	8	8
Recurring | Commodity | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3	3
Derivative liabilities	5	5
Recurring | Commodity | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	36	77
Derivative liabilities	43	93
Recurring | Commodity | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	28	40
Derivative liabilities	30	57
Recurring | Commodity | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	7	7
Derivative liabilities	20	6
Recurring | Commodity | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1	4
Derivative liabilities	3	0
Recurring | Interest Rate Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2
Derivative liabilities	6	0
Recurring | Interest Rate Swaps | Netting Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Interest Rate Swaps | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Interest Rate Swaps | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2
Derivative liabilities	6	0
Recurring | Interest Rate Swaps | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	401	403
Recurring | Other | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	376	374
Recurring | Other | Netting Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Other | Netting Adjustment | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	287	283
Recurring | Other | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	267	260
Recurring | Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	114	120
Recurring | Other | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	109	114
Recurring | Other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Other | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Commodity Derivatives (Details) - Level 3 $ in Millions	Dec. 31, 2018USD ($)$ / kW-month$ / MWh
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ (13)
CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	(2)
Electricity | Forward Energy Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ (12)
Electricity | Forward Energy Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	21.34
Electricity | Forward Energy Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	64.45
Electricity | Forward Capacity Prices | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ (3)
Electricity | Forward Capacity Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	1
Electricity | Forward Capacity Prices | Minimum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	1
Electricity | Forward Capacity Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	6.30
Electricity | Forward Capacity Prices | Maximum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	6.30
Natural Gas | Forward Energy Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ (2)
Natural Gas | Forward Natural Gas Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	0.92
Natural Gas | Forward Natural Gas Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / kW-month	6.62
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 1
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 1
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	0.29
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Minimum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	0.49
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	8.03
Transmission Congestion Contracts | Inter-Zonal Forward Price Curves | Maximum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per unit) | $ / MWh	2.60

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 1	$ 1
Included in earnings	4	8
Included in regulatory assets and liabilities	(10)	(13)
Purchases	0	2
Settlements	(6)	(8)
Transfer out of level 3	(2)	11
Ending Balance	(13)	1
CECONY
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	4	1
Included in earnings	4	2
Included in regulatory assets and liabilities	(4)	(7)
Purchases	0	1
Settlements	(4)	(3)
Transfer out of level 3	(2)	10
Ending Balance	$ (2)	$ 4

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - Clean Energy Businesses - Non-utility revenue - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) on Level 3 energy derivative assets and liabilities	$ (3)	$ 2
Fair value, assets and liabilities measured on recurring basis, change in unrealized gain (loss)	$ (3)	$ 2

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)MW	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Noncontrolling interest	$ 113	$ 7
Texas Solar 4 | Noncontrolling Interest
Variable Interest Entity [Line Items]
Noncontrolling interest	$ 7
Texas Solar 4 | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Generating capacity (MW AC) | MW	40
VIE consolidated, carrying amount, assets and liabilities, net	$ 27	$ 26
Texas Solar 4 | Variable Interest Entity, Primary Beneficiary | Con Edison Development
Variable Interest Entity [Line Items]
Percentage of variable interests (less than)	80.00%
Tax Equity Projects | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
VIE consolidated, carrying amount, assets and liabilities, net	$ 870
Noncontrolling interest	$ 104
Tax Equity Projects | Variable Interest Entity, Primary Beneficiary | Con Edison Development
Variable Interest Entity [Line Items]
Percentage of variable interests (less than)	100.00%

Variable Interest Entities - Ne

Variable Interest Entities - Net Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Great Valley Solar
Business Acquisition [Line Items]
Restricted cash	$ 0
Non-utility property, less accumulated depreciation of $1 for each of the Tax Equity Projects and $15 and $12, for Texas Solar 4 in 2018 and 2017, respectively	313
Other assets	18
Total assets	331
Long-term debt due within one year	0
Other liabilities	17
Long-term debt	0
Total liabilities	17
Accumulated depreciation	1
Copper Mountain Solar - Mesquite Solar
Business Acquisition [Line Items]
Restricted cash	0
Non-utility property, less accumulated depreciation of $1 for each of the Tax Equity Projects and $15 and $12, for Texas Solar 4 in 2018 and 2017, respectively	492
Other assets	97
Total assets	589
Long-term debt due within one year	0
Other liabilities	33
Long-term debt	0
Total liabilities	33
Accumulated depreciation	1
Texas Solar 4
Business Acquisition [Line Items]
Restricted cash	4	$ 5
Non-utility property, less accumulated depreciation of $1 for each of the Tax Equity Projects and $15 and $12, for Texas Solar 4 in 2018 and 2017, respectively	98	101
Other assets	9	8
Total assets	111	114
Long-term debt due within one year	2	2
Other liabilities	26	28
Long-term debt	56	58
Total liabilities	84	88
Accumulated depreciation	$ 15	$ 12

Variable Interest Entities - Su

Variable Interest Entities - Summary of VIEs (Details)	12 Months Ended
	Dec. 31, 2018USD ($)MW
Variable Interest Entity, Not Primary Beneficiary | Great Valley Solar
Variable Interest Entity [Line Items]
Generating Capacity Owned (MW AC) | MW	200
Maximum Exposure to Loss	$ 281,000,000
Variable Interest Entity, Not Primary Beneficiary | Great Valley Solar | Minimum
Variable Interest Entity [Line Items]
Power Purchase Agreement Term in Years	15 years
Variable Interest Entity, Not Primary Beneficiary | Great Valley Solar | Maximum
Variable Interest Entity [Line Items]
Power Purchase Agreement Term in Years	20 years
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar - Mesquite Solar
Variable Interest Entity [Line Items]
Generating Capacity Owned (MW AC) | MW	344
Maximum Exposure to Loss	$ 485,000,000
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar - Mesquite Solar | Minimum
Variable Interest Entity [Line Items]
Power Purchase Agreement Term in Years	20 years
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar - Mesquite Solar | Maximum
Variable Interest Entity [Line Items]
Power Purchase Agreement Term in Years	25 years
Variable Interest Entity, Primary Beneficiary | Great Valley Solar
Variable Interest Entity [Line Items]
Maximum exposure for consolidated investments	$ 33,000,000
Variable Interest Entity, Primary Beneficiary | Copper Mountain Solar - Mesquite Solar
Variable Interest Entity [Line Items]
Maximum exposure for consolidated investments	$ 71,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4
Variable Interest Entity [Line Items]
Generating Capacity Owned (MW AC) | MW	32
Power Purchase Agreement Term in Years	25 years
Maximum Exposure to Loss	$ 20,000,000
Maximum exposure for consolidated investments	$ 7,000,000

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Regulatory Liabilities [Line Items]
Accrued liability - asset retirement obligations	$ 450	$ 314
Increase in liabilities for asset retirement obligations due to changes in estimated cash flows	168
Asset retirement obligations, accretion expense	13
Asset retirement obligations, liabilities settled	45
Asset retirement obligations, reductions	50	36
CECONY
Regulatory Liabilities [Line Items]
Accrued liability - asset retirement obligations	292	287
Increase in liabilities for asset retirement obligations due to changes in estimated cash flows	39
Asset retirement obligations, accretion expense	11
Asset retirement obligations, liabilities settled	45
Asset retirement obligations, reductions	$ 50	$ 36

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)MMBTUagreement	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 31, 2016
CECONY
Related Party Transaction [Line Items]
Net assets	$ 12,910,000,000
Sale of natural gas	83,000,000	$ 66,000,000	$ 47,000,000
Funding limit of CECONY to O&R (not to exceed)	$ 250,000,000
CECONY | Related Party, Lending of Funds
Related Party Transaction [Line Items]
Lending period (not more than) (months)	12 months
CECONY | Equity Method Investee | Mountain Valley Pipeline
Related Party Transaction [Line Items]
Amount of transaction	$ 0	0
Contract term (years)	20 years
Generating capacity per day (in dekatherms) | MMBTU	250,000
CECONY | Equity Method Investee | Stagecoach | Purchased Power Costs
Related Party Transaction [Line Items]
Amount of transaction	$ 28,000,000	31,000,000	$ 18,000,000
CECONY | Equity Method Investee | Stagecoach | Purchased Power Costs | Clean Energy Businesses
Related Party Transaction [Line Items]
Number of electricity sales agreements entered into | agreement	2
CECONY | Affiliated Entity | Financial Electric Capacity Contract | Con Edison Energy
Related Party Transaction [Line Items]
Gain (loss) on financial electric capacity contracts	$ (1,000,000)	3,000,000
O&R
Related Party Transaction [Line Items]
Net assets	712,000,000
Outstanding loans	$ 0	$ 0
CET Electric | NY Transco
Related Party Transaction [Line Items]
Ownership interest, percentage	45.70%
CET Gas | Mountain Valley Pipeline
Related Party Transaction [Line Items]
Percentage of equity interest owned	12.50%			12.50%

Related Party Transactions - Su

Related Party Transactions - Summary of Costs of Administrative and Other Services Provided and Received (Details) - CECONY - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Cost of services provided	$ 115	$ 111	$ 108
Cost of services received	$ 73	$ 64	$ 64

New Financial Accounting Stan_2

New Financial Accounting Standards (Details) - Scenario, Forecast - ASU 2016-02 $ in Millions	Jan. 01, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset	$ 875
Lease liabilities	875
CECONY
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset	635
Lease liabilities	$ 635

Acquisitions, Investments and_3

Acquisitions, Investments and Dispositions - Mountain Valley Pipeline (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Equity method investment		$ 0	$ 467
Mountain Valley Pipeline | Maximum
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity interest		$ 4,600
CET Gas | Mountain Valley Pipeline
Schedule of Equity Method Investments [Line Items]
Percentage of equity interest acquired	12.50%	12.50%
Payments to acquire equity interest	$ 18
Equity method investment		$ 363	$ 98

Acquisitions, Investments and_4

Acquisitions, Investments and Dispositions - Pilesgrove (Details) $ in Millions	1 Months Ended		12 Months Ended
	Aug. 31, 2016USD ($)	Jun. 30, 2016USD ($)MW	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Bargain purchase gain			$ 131	$ 0	$ 0
Pilesgrove
Business Acquisition [Line Items]
Generating capacity (MW AC) | MW		18
Net assets			$ 45
Con Edison Development | Pilesgrove
Business Acquisition [Line Items]
Percentage of voting interest acquired	50.00%
Purchase price	$ 16
Bargain purchase gain	8
Bargain purchase gain, net of taxes	5
Non-utility property	45
Other current assets	$ 3
Con Edison Development | Pilesgrove
Business Acquisition [Line Items]
Equity method investment, impairment charge		$ 8
Equity method investment, impairment charge, net of taxes		$ 5
Percentage of equity interest owned		50.00%

Acquisitions, Investments and_5

Acquisitions, Investments and Dispositions - Sempra Solar (Details) $ / shares in Units, $ in Millions	Dec. 13, 2018USD ($)$ / sharesMW	Dec. 12, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Business acquisition, pre-tax gain from interests in projects	$ 131		$ 131
Long-term debt			$ 16,029	$ 18,145
Sempra Solar
Business Acquisition [Line Items]
Ownership percentage	50.00%
Renewable Electric Production Projects | Sempra Solar
Business Acquisition [Line Items]
Project generating capacity (MW AC) | MW	379
Sempra Solar
Business Acquisition [Line Items]
Business acquisition, pre-tax gain from interests in projects	$ 131
Business acquisition, after-tax gain from interests in projects	$ 89
Business acquisition, after-tax gain from interests in projects, per share (in dollars per share) | $ / shares	$ 0.28
Con Edison Development | Sempra Solar
Business Acquisition [Line Items]
Purchase price	$ 1,609
Working capital and other closing adjustments	69
Acquisition-date fair value of ownership interest held	568	$ 437
Property, plant and equipment acquired	1,454
Intangible assets acquired	878
Noncurrent assets	$ 4
Weighted average amortization period for intangible assets	16 years
Fair value of noncontrolling interest attributable to tax equity investors	$ 100
Sempra Solar | Renewable Electric Production Projects
Business Acquisition [Line Items]
Project generating capacity (MW AC) | MW	981
Long-term debt	$ 568
Asset retirement obligation	$ 128

Acquisitions, Investments and_6

Acquisitions, Investments and Dispositions - Pro Forma Supplemental Information (Details) - USD ($) $ in Millions	Dec. 13, 2018	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Revenues			$ 12,337	$ 12,033	$ 12,075
Net income			1,382	1,525	$ 1,245
If Acquired January 1, 2017 (a)(b)
Revenue			12,655	12,331
Net income			1,279	1,612
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Interest expense			37	38
Business acquisition, pre-tax gain from interests in projects	$ 131			131
Pro Forma
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Income from equity method investment			33	$ 32
Term Loan
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Short-term borrowings		$ 825	$ 825
Fixed interest rate		4.64%	4.64%

Acquisitions, Investments and_7

Acquisitions, Investments and Dispositions - Con Edison Solutions' Retail Electric Supply Business (Details) - Con Edison Solutions - Retail Electric Supply Business - Discontinued Operations, Disposed of by Sale $ in Millions	1 Months Ended
	Sep. 30, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of business	$ 235
Gain on sale of business	104
Gain on sale of business, after tax	56
Gain on sale of derivatives	65
Gain on sale of derivatives, after tax	42
Tax effect of sale, state tax related to change in apportionment of state income taxes	16
Tax effect of sale, state tax related to change in apportionment of state income taxes, net of federal tax	$ 10

Acquisitions, Investments and_8

Acquisitions, Investments and Dispositions - Upton 2 (Details) - Con Edison Development $ in Millions	1 Months Ended	12 Months Ended
	May 31, 2017USD ($)	Dec. 31, 2018MW
Upton 2
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Generating capacity (MW AC) | MW		180
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Upton 2
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration the project is sold	$ 11
Gain on sale of project	1
Gain on sale of project, net of tax	$ 0.7

Schedule I - Condensed Financ_2

Schedule I - Condensed Financial Information - Income and Comprehensive Income (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Income Statements,Captions [Line Items]
Interest expense	$ (819)	$ (729)	$ (696)
NET INCOME	1,382	1,525	1,245
Comprehensive Income	$ 1,392	$ 1,526	$ 1,252
Net Income Per Share – Basic (in dollars per share)	$ 4.43	$ 4.97	$ 4.15
Net Income Per Share – Diluted (in dollars per share)	$ 4.42	$ 4.94	$ 4.12
Average Number Of Shares Outstanding—Basic (in shares)	311.7	307.1	300.4
Average Number Of Shares Outstanding—Diluted (in shares)	312.9	308.8	301.9
Parent Company
Condensed Income Statements,Captions [Line Items]
Equity in earnings of subsidiaries	$ 1,447	$ 1,544	$ 1,254
Other income (deductions), net of taxes	(6)	31	32
Interest expense	(59)	(50)	(41)
NET INCOME	1,382	1,525	1,245
Comprehensive Income	$ 1,392	$ 1,526	$ 1,252
Net Income Per Share – Basic (in dollars per share)	$ 4.43	$ 4.97	$ 4.15
Net Income Per Share – Diluted (in dollars per share)	4.42	4.94	4.12
Dividends Declared Per Share (in dollars per share)	$ 2.86	$ 2.76	$ 2.68
Average Number Of Shares Outstanding—Basic (in shares)	311.7	307.1	300.4
Average Number Of Shares Outstanding—Diluted (in shares)	312.9	308.8	301.9

Schedule I - Condensed Financ_3

Schedule I - Condensed Financial Information - Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net Income	$ 1,382	$ 1,525	$ 1,245
Change in Assets:
Taxes receivable	27	15	87
Other – net	(62)	0	69
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,695	3,367	3,459
INVESTING ACTIVITIES
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(5,471)	(3,710)	(4,950)
FINANCING ACTIVITIES
Net proceeds of short-term debt	1,989	(477)	(475)
Issuance of long-term debt	3,030	1,697	2,590
Retirement of long-term debt	(1,938)	(434)	(735)
Debt issuance costs	(61)	(19)	(24)
Issuance of common shares for stock plans	53	51	51
Issuance of common shares - public offering	705	343	702
Common stock dividends	(842)	(803)	(763)
NET CASH FLOWS FROM FINANCING ACTIVITIES	2,938	357	1,345
BALANCE AT BEGINNING OF PERIOD	797
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	895	797
CECONY
Condensed Cash Flow Statements, Captions [Line Items]
Net Income	1,196	1,104	1,056
Change in Assets:
Other – net	(96)	23	(11)
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,204	2,866	3,038
INVESTING ACTIVITIES
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,306)	(3,080)	(2,753)
FINANCING ACTIVITIES
Net proceeds of short-term debt	1,042	(450)	(433)
Issuance of long-term debt	2,740	1,200	1,300
Retirement of long-term debt	(1,836)	0	(650)
Debt issuance costs	(30)	(15)	(13)
NET CASH FLOWS FROM FINANCING ACTIVITIES	1,190	240	(440)
BALANCE AT BEGINNING OF PERIOD	730
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	818	730
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net Income	1,382	1,525	1,245
Equity in earnings of subsidiaries	(1,447)	(1,544)	(1,254)
Change in Assets:
Special deposits	(8)	0	0
Taxes receivable	2	34	87
Other – net	187	21	(152)
NET CASH FLOWS FROM OPERATING ACTIVITIES	1,033	896	723
INVESTING ACTIVITIES
Contributions to subsidiaries	(1,110)	(434)	(691)
Debt receivable from affiliated companies	(825)	0	(900)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(1,935)	(434)	(1,591)
FINANCING ACTIVITIES
Net proceeds of short-term debt	164	(53)	(53)
Issuance of long-term debt	825	400	900
Retirement of long-term debt	(3)	(402)	(2)
Debt issuance costs	0	(2)	(5)
Issuance of common shares for stock plans	53	51	51
Issuance of common shares - public offering	705	343	702
Common stock dividends	(842)	(803)	(763)
NET CASH FLOWS FROM FINANCING ACTIVITIES	902	(466)	830
NET CHANGE FOR THE PERIOD	0	(4)	(38)
BALANCE AT BEGINNING OF PERIOD	9	13	51
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	9	9	13
Parent Company | CECONY
Condensed Cash Flow Statements, Captions [Line Items]
Dividends received	846	796	744
Parent Company | O&R
Condensed Cash Flow Statements, Captions [Line Items]
Dividends received	46	44	43
Parent Company | Clean Energy Businesses
Condensed Cash Flow Statements, Captions [Line Items]
Dividends received	15	12	10
Parent Company | Con Edison Transmission
Condensed Cash Flow Statements, Captions [Line Items]
Dividends received	$ 10	$ 8	$ 0

Schedule I - Condensed Financ_4

Schedule I - Condensed Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current Assets
Cash and temporary cash investments	$ 895	$ 797
Taxes receivable	49	76
Prepayments	187	178
Other current assets	122	177
TOTAL CURRENT ASSETS	3,864	3,537
Investments in subsidiaries	1,766	2,001
Goodwill	440	428
Other noncurrent assets	6,541	4,973
TOTAL ASSETS	53,920	48,111	$ 48,255
Current Liabilities
Long-term debt due within one year	650	1,298
Term Loan	825	0
Notes payable	1,741	577
Accounts payable	1,187	1,286
Accrued taxes	61	108
Other current liabilities	363	386
TOTAL CURRENT LIABILITIES	6,207	4,902
Long-term debt	17,495	14,731
Shareholders’ Equity
Equity	16,726	15,418
TOTAL LIABILITIES AND EQUITY	53,920	48,111
Parent Company
Current Assets
Cash and temporary cash investments	9	9	$ 13	$ 51
Taxes receivable	43	45
Term loan receivable from affiliated companies	825	0
Accounts receivable from affiliated companies	536	687
Prepayments	33	36
Other current assets	12	18
TOTAL CURRENT ASSETS	1,458	795
Investments in subsidiaries	16,707	15,110
Goodwill	406	406
Deferred income tax	69	18
Long-term debt receivable from affiliated companies	900	900
Other noncurrent assets	2	2
TOTAL ASSETS	19,542	17,231
Current Liabilities
Long-term debt due within one year	3	2
Term Loan	825	0
Notes payable	495	331
Accounts payable	9	0
Accounts payable to affiliated companies	274	274
Accrued taxes	2	0
Other current liabilities	13	10
TOTAL CURRENT LIABILITIES	1,621	617
Total Liabilities	1,621	617
Long-term debt	1,195	1,195
Shareholders’ Equity
Common stock, including additional paid-in capital	7,151	6,331
Retained earnings	9,575	9,088
Equity	16,726	15,419
TOTAL LIABILITIES AND EQUITY	$ 19,542	$ 17,231

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance For Uncollectible Accounts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 70	$ 83	$ 96
Charged To Costs And Expenses	62	64	63
Charged To Other Accounts	0	0	0
Deductions	64	77	76
Balance At End of Period	68	70	83
CECONY
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	65	78	91
Charged To Costs And Expenses	56	60	57
Charged To Other Accounts	0	0	0
Deductions	60	73	70
Balance At End of Period	$ 61	$ 65	$ 78