Consolidated Edison (ED) 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 28, 2016
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	ED
Entity Registrant Name	CONSOLIDATED EDISON INC
Entity Central Index Key	1,047,862
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		304,727,523
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 Filer Category	Non-accelerated Filer

Consolidated Income Statement (

Consolidated Income Statement (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
OPERATING REVENUES
Electric	$ 2,769	$ 2,762	$ 6,717	$ 6,937
Gas	235	237	1,246	1,293
Steam	63	58	406	529
Non-utility	350	386	999	1,088
TOTAL OPERATING REVENUES	3,417	3,443	9,368	9,847
OPERATING EXPENSES
Purchased power	798	860	2,047	2,404
Fuel	29	31	133	216
Gas purchased for resale	81	64	320	415
Other operations and maintenance	840	869	2,447	2,485
Depreciation and amortization	305	285	905	840
Taxes, other than income taxes	528	504	1,523	1,459
TOTAL OPERATING EXPENSES	2,581	2,613	7,375	7,819
Gain on sale of retail electric supply business	104	0	104	0
OPERATING INCOME	940	830	2,097	2,028
OTHER INCOME (DEDUCTIONS)
Investment and other income	51	12	70	31
Allowance for equity funds used during construction	3	1	7	3
Other deductions	(5)	(4)	(16)	(11)
TOTAL OTHER INCOME (DEDUCTIONS)	49	9	61	23
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	989	839	2,158	2,051
INTEREST EXPENSE
Interest on long-term debt	174	157	504	469
Other interest	5	6	17	19
Allowance for borrowed funds used during construction	(1)	(1)	(4)	(2)
NET INTEREST EXPENSE	178	162	517	486
INCOME BEFORE INCOME TAX EXPENSE	811	677	1,641	1,565
INCOME TAX EXPENSE	314	249	602	548
NET INCOME	$ 497	$ 428	$ 1,039	$ 1,017
Net income per common share-basic (dollars per share)	$ 1.63	$ 1.46	$ 3.47	$ 3.47
Net income per common share-diluted (dollars per share)	1.62	1.45	3.46	3.46
DIVIDENDS DECLARED PER COMMON SHARE (dollars per share)	$ 0.67	$ 0.65	$ 2.01	$ 1.95
AVERAGE NUMBER OF SHARES OUTSTANDING-BASIC (IN MILLIONS) (shares)	304.5	292.9	299.1	292.9
AVERAGE NUMBER OF SHARES OUTSTANDING—DILUTED (IN MILLIONS) (shares)	305.9	294.2	300.5	294.2
CECONY
OPERATING REVENUES
Electric	$ 2,557	$ 2,558	$ 6,222	$ 6,416
Gas	208	213	1,113	1,177
Steam	63	58	406	529
TOTAL OPERATING REVENUES	2,828	2,829	7,741	8,122
OPERATING EXPENSES
Purchased power	495	526	1,216	1,423
Fuel	29	31	133	216
Gas purchased for resale	34	30	217	282
Other operations and maintenance	724	750	2,105	2,140
Depreciation and amortization	278	262	825	773
Taxes, other than income taxes	502	485	1,446	1,399
TOTAL OPERATING EXPENSES	2,062	2,084	5,942	6,233
OPERATING INCOME	766	745	1,799	1,889
OTHER INCOME (DEDUCTIONS)
Investment and other income	4	(1)	6	3
Allowance for equity funds used during construction	2	1	6	3
Other deductions	(4)	(3)	(10)	(10)
TOTAL OTHER INCOME (DEDUCTIONS)	2	(3)	2	(4)
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	768	742	1,801	1,885
INTEREST EXPENSE
Interest on long-term debt	150	141	440	423
Other interest	5	5	14	14
Allowance for borrowed funds used during construction	(1)	(1)	(3)	(2)
NET INTEREST EXPENSE	154	145	451	435
INCOME BEFORE INCOME TAX EXPENSE	614	597	1,350	1,450
INCOME TAX EXPENSE	226	222	491	515
NET INCOME	$ 388	$ 375	$ 859	$ 935

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
NET INCOME	$ 497	$ 428	$ 1,039	$ 1,017
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	1	1	2	7
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2	7
COMPREHENSIVE INCOME	498	429	1,041	1,024
CECONY
NET INCOME	388	375	859	935
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	0	1	1	2
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	0	1	1	2
COMPREHENSIVE INCOME	$ 388	$ 376	$ 860	$ 937

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
OPERATING ACTIVITIES
NET INCOME	$ 1,039	$ 1,017
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	905	840
Deferred income taxes	524	466
Rate case amortization and accruals	(157)	(38)
Common equity component of allowance for funds used during construction	(7)	(3)
Net derivative (gains)/losses	(7)	(4)
Pre-tax gain on sale of retail electric supply business	(104)	0
Other non-cash items, net	99	73
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(138)	(82)
Materials and supplies, including fuel oil and gas in storage	15	32
Other receivables and other current assets	90	44
Income taxes receivable	100	194
Prepayments	(403)	(568)
Accounts payable	142	83
Pensions and retiree benefits obligations, net	464	566
Pensions and retiree benefits contributions	(510)	(753)
Accrued taxes	(21)	(19)
Accrued interest	66	48
Superfund and environmental remediation costs, net	68	23
Distributions from equity investments	45	29
Deferred charges, noncurrent assets and other regulatory assets	(104)	(17)
Deferred credits and other regulatory liabilities	116	220
Other current and noncurrent liabilities	114	48
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,336	2,199
INVESTING ACTIVITIES
Utility construction expenditures	(2,057)	(1,838)
Cost of removal less salvage	(149)	(156)
Non-utility construction expenditures	(436)	(366)
Investments in/acquisitions of renewable electric production and electric and gas transmission projects	(1,281)	(286)
Proceeds from sale of assets	250	0
Proceeds from the transfer of assets to NY Transco	122	0
Restricted cash	(21)	(23)
Other investing activities	(145)	(18)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(3,717)	(2,687)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	(928)	360
Issuance of long-term debt	1,765	238
Retirement of long-term debt	(407)	(145)
Debt issuance costs	(16)	(2)
Common stock dividends	(570)	(560)
Issuance of common shares - public offering	702	0
Issuance of common shares for stock plans, net of repurchases	38	(9)
Distribution to noncontrolling interest	(1)	0
NET CASH FLOWS FROM/(USED IN) FINANCING ACTIVITIES	583	(118)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(798)	(606)
BALANCE AT BEGINNING OF PERIOD	944	699
BALANCE AT END OF PERIOD	146	93
LESS: CHANGE IN CASH BALANCES HELD FOR SALE	(4)	2
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	150	91
Cash paid/(received) during the period for:
Interest	437	411
Income taxes	(144)	(7)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	242	204
Issuance of common shares for dividend reinvestment	35	11
CECONY
OPERATING ACTIVITIES
NET INCOME	859	935
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	825	773
Deferred income taxes	569	391
Rate case amortization and accruals	(170)	(57)
Common equity component of allowance for funds used during construction	(6)	(3)
Other non-cash items, net	7	13
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(79)	(51)
Materials and supplies, including fuel oil and gas in storage	15	34
Other receivables and other current assets	18	60
Accounts receivable from affiliated companies	38	(32)
Prepayments	(351)	(336)
Accounts payable	82	18
Accounts payable to affiliated companies	8	5
Pensions and retiree benefits obligations, net	439	530
Pensions and retiree benefits contributions	(472)	(700)
Accrued taxes	(17)	(1)
Accrued interest	43	37
Superfund and environmental remediation costs, net	76	21
Accrued taxes to affiliated companies	(2)	(8)
Deferred charges, noncurrent assets and other regulatory assets	(153)	(49)
Deferred credits and other regulatory liabilities	165	222
Other current and noncurrent liabilities	123	0
NET CASH FLOWS FROM OPERATING ACTIVITIES	2,017	1,802
INVESTING ACTIVITIES
Utility construction expenditures	(1,932)	(1,732)
Cost of removal less salvage	(146)	(149)
Proceeds from the transfer of assets to NY Transco	122	0
Restricted cash	13	(19)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(1,943)	(1,900)
FINANCING ACTIVITIES
Net (payment)/issuance of short-term debt	(553)	199
Issuance of long-term debt	550	0
Retirement of long-term debt	(400)	0
Debt issuance costs	(6)	(1)
Capital contribution by parent	76	0
Dividend to parent	(558)	(694)
NET CASH FLOWS FROM/(USED IN) FINANCING ACTIVITIES	(891)	(496)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(817)	(594)
BALANCE AT BEGINNING OF PERIOD	843	645
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	26	51
Cash paid/(received) during the period for:
Interest	386	376
Income taxes	(130)	143
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	$ 195	$ 152

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
CURRENT ASSETS
Cash and temporary cash investments	$ 150	$ 944
Special deposits	3	3
Accounts receivable - customers, less allowance for uncollectible accounts	1,157	1,052
Other receivables, less allowance for uncollectible accounts	165	304
Income taxes receivable	66	166
Accrued unbilled revenue	373	360
Fuel oil, gas in storage, materials and supplies, at average cost	335	350
Prepayments	580	177
Regulatory assets	119	132
Assets held for sale	0	157
Other current assets	206	191
TOTAL CURRENT ASSETS	3,154	3,836
INVESTMENTS	1,931	884
UTILITY PLANT, AT ORIGINAL COST
General	2,657	2,622
TOTAL	39,523	38,174
Less: Accumulated depreciation	8,451	8,044
Net	31,072	30,130
Construction work in progress	1,286	1,003
NET UTILITY PLANT	32,358	31,133
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	1,127	832
Construction work in progress	421	244
NET PLANT	33,906	32,209
OTHER NONCURRENT ASSETS
Goodwill	429	429
Intangible assets, less accumulated amortization of $5 and $4 in 2016 and 2015, respectively	0	2
Regulatory assets	7,544	8,096
Other deferred charges and noncurrent assets	352	186
TOTAL OTHER NONCURRENT ASSETS	8,325	8,713
TOTAL ASSETS	47,316	45,642
CURRENT LIABILITIES
Long-term debt due within one year	346	739
Notes payable	601	1,529
Accounts payable	1,113	1,008
Customer deposits	356	354
Accrued taxes	41	62
Accrued interest	202	136
Accrued wages	101	97
Fair value of derivative liabilities	70	66
Regulatory liabilities	123	115
Liabilities held for sale	0	89
Other current liabilities	638	525
TOTAL CURRENT LIABILITIES	3,591	4,720
NONCURRENT LIABILITIES
Provision for injuries and damages	170	185
Pensions and retiree benefits	2,197	2,911
Superfund and other environmental costs	752	765
Asset retirement obligations	254	242
Fair value of derivative liabilities	52	39
Deferred income taxes and unamortized investment tax credits	10,155	9,537
Regulatory liabilities	1,920	1,977
Other deferred credits and noncurrent liabilities	203	199
TOTAL NONCURRENT LIABILITIES	15,703	15,855
LONG-TERM DEBT	13,747	12,006
EQUITY
Common shareholders’ equity	14,267	13,052
Noncontrolling interest	8	9
TOTAL EQUITY (See Statement of Equity)	14,275	13,061
TOTAL LIABILITIES AND EQUITY	47,316	45,642
CECONY
CURRENT ASSETS
Cash and temporary cash investments	26	843
Special deposits	2	2
Accounts receivable - customers, less allowance for uncollectible accounts	1,076	987
Other receivables, less allowance for uncollectible accounts	55	70
Accrued unbilled revenue	330	327
Accounts receivable from affiliated companies	152	190
Fuel oil, gas in storage, materials and supplies, at average cost	273	288
Prepayments	464	113
Regulatory assets	111	121
Other current assets	98	131
TOTAL CURRENT ASSETS	2,587	3,072
INVESTMENTS	318	286
UTILITY PLANT, AT ORIGINAL COST
General	2,437	2,411
TOTAL	37,023	35,766
Less: Accumulated depreciation	7,750	7,378
Net	29,273	28,388
Construction work in progress	1,200	922
NET UTILITY PLANT	30,473	29,310
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	4	5
NET PLANT	30,477	29,315
OTHER NONCURRENT ASSETS
Regulatory assets	6,986	7,482
Other deferred charges and noncurrent assets	68	75
TOTAL OTHER NONCURRENT ASSETS	7,054	7,557
TOTAL ASSETS	40,436	40,230
CURRENT LIABILITIES
Long-term debt due within one year	250	650
Notes payable	480	1,033
Accounts payable	838	771
Accounts payable to affiliated companies	20	12
Customer deposits	341	339
Accrued taxes	32	49
Accrued taxes to affiliated companies	0	2
Accrued interest	161	118
Accrued wages	92	88
Fair value of derivative liabilities	61	50
Regulatory liabilities	96	84
Other current liabilities	558	443
TOTAL CURRENT LIABILITIES	2,929	3,639
NONCURRENT LIABILITIES
Provision for injuries and damages	164	178
Pensions and retiree benefits	1,895	2,565
Superfund and other environmental costs	661	665
Asset retirement obligations	241	234
Fair value of derivative liabilities	45	36
Deferred income taxes and unamortized investment tax credits	9,472	8,755
Regulatory liabilities	1,725	1,789
Other deferred credits and noncurrent liabilities	177	167
TOTAL NONCURRENT LIABILITIES	14,380	14,389
LONG-TERM DEBT	11,334	10,787
EQUITY
Common shareholders’ equity	11,793	11,415
TOTAL LIABILITIES AND EQUITY	40,436	40,230
Electric
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	27,239	26,358
Electric | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	25,648	24,828
OTHER NONCURRENT ASSETS
TOTAL ASSETS	30,580
Gas
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	7,253	6,858
Gas | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	6,564	6,191
OTHER NONCURRENT ASSETS
TOTAL ASSETS	7,300
Steam
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,374	2,336
Steam | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,374	$ 2,336
OTHER NONCURRENT ASSETS
TOTAL ASSETS	$ 2,556

Consolidated Balance Sheet (Un6

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable - customers, allowance for uncollectible accounts	$ 75	$ 85
Other receivables, allowance for uncollectible accounts	13	11
Non-utility property, accumulated depreciation	122	95
Intangible assets, accumulated amortization	5	4
CECONY
Accounts receivable - customers, allowance for uncollectible accounts	70	80
Other receivables, allowance for uncollectible accounts	12	11
Non-utility property, accumulated depreciation	$ 25	$ 25

Consolidated Statement of Equit

Consolidated Statement of Equity/Shareholder's Equity (Unaudited) - USD ($) $ in Millions	Total	CECONY	Common Stock	Common StockCECONY	Additional Paid-In Capital	Additional Paid-In CapitalCECONY	Retained Earnings	Retained EarningsCECONY	Repurchased Con Edison StockCECONY	Treasury Stock	Capital Stock Expense	Capital Stock ExpenseCECONY	Accumulated Other Comprehensive Income/(Loss)	Accumulated Other Comprehensive Income/(Loss)CECONY	Noncontrolling Interest
Beginning Balance at Dec. 31, 2014	$ 12,585		$ 32		$ 4,991		$ 8,691			$ (1,032)	$ (61)		$ (45)	$ (11)	$ 9
Beginning Balance at Dec. 31, 2014		$ 11,188		$ 589		$ 4,234		$ 7,399	$ (962)			$ (61)		(11)
Beginning Balance (in shares) at Dec. 31, 2014			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	370	348					370	348
Common stock dividends	(190)	(338)					(190)	(338)
Issuance of common shares for stock plans, net of repurchases					2					$ (2)
Other comprehensive income	5	0											5	0
Ending Balance at Mar. 31, 2015		11,198		$ 589		4,234		7,409	(962)			(61)		(11)
Ending Balance at Mar. 31, 2015	12,770		$ 32		4,993		8,871			$ (1,034)	(61)		(40)		9
Ending Balance (in shares) at Mar. 31, 2015			293,000,000	235,000,000						23,000,000
Beginning Balance at Dec. 31, 2014	12,585		$ 32		4,991		8,691			$ (1,032)	(61)		(45)	(11)	9
Beginning Balance at Dec. 31, 2014		11,188		$ 589		4,234		7,399	(962)			(61)		(11)
Beginning Balance (in shares) at Dec. 31, 2014			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,017	935
Ending Balance at Sep. 30, 2015		11,430		$ 589		4,234		7,639	(962)			(61)		(9)
Ending Balance at Sep. 30, 2015	13,049		$ 32		5,008		9,137			$ (1,038)	(61)		(38)	(9)	9
Ending Balance (in shares) at Sep. 30, 2015			293,000,000	235,000,000						23,000,000
Beginning Balance at Mar. 31, 2015	12,770		$ 32		4,993		8,871			$ (1,034)	(61)		(40)		9
Beginning Balance at Mar. 31, 2015		11,198		$ 589		4,234		7,409	(962)			(61)		(11)
Beginning Balance (in shares) at Mar. 31, 2015			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	219	211					219	211
Common stock dividends	(190)	(178)					(190)	(178)
Issuance of common shares for stock plans, net of repurchases	(3)									$ (3)
Other comprehensive income	1	1											1	1
Ending Balance at Jun. 30, 2015		11,232		$ 589		4,234		7,442	(962)			(61)		(10)
Ending Balance at Jun. 30, 2015	12,797		$ 32		4,993		8,900			$ (1,037)	(61)		(39)	(10)	9
Ending Balance (in shares) at Jun. 30, 2015			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	428	375					428	375
Common stock dividends	(191)	(178)					(191)	(178)
Issuance of common shares for stock plans, net of repurchases	14				15					$ (1)
Other comprehensive income	1	1											1	1
Ending Balance at Sep. 30, 2015		11,430		$ 589		4,234		7,639	(962)			(61)		(9)
Ending Balance at Sep. 30, 2015	13,049		$ 32		5,008		9,137			$ (1,038)	(61)		(38)	(9)	9
Ending Balance (in shares) at Sep. 30, 2015			293,000,000	235,000,000						23,000,000
Beginning Balance at Dec. 31, 2015	13,061		$ 32		5,030		9,123			$ (1,038)	(61)		(34)	(9)	9
Beginning Balance at Dec. 31, 2015	13,052	11,415		$ 589		4,247		7,611	(962)			(61)		(9)
Beginning Balance (in shares) at Dec. 31, 2015			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	310	310					310	310
Common stock dividends	(197)	(186)					(197)	(186)
Issuance of common shares for stock plans, net of repurchases	28				28
Issuance of common shares for stock plans, net of repurchases (in shares)			1,000,000
Capital contribution by parent		23				23
Other comprehensive income	0	0											0	0
Noncontrolling interest	(1)														(1)
Ending Balance at Mar. 31, 2016		11,562		$ 589		4,270		7,735	(962)			(61)		(9)
Ending Balance at Mar. 31, 2016	13,201		$ 32		5,058		9,236			$ (1,038)	(61)		(34)		8
Ending Balance (in shares) at Mar. 31, 2016			294,000,000	235,000,000						23,000,000
Beginning Balance at Dec. 31, 2015	13,061		$ 32		5,030		9,123			$ (1,038)	(61)		(34)	(9)	9
Beginning Balance at Dec. 31, 2015	13,052	11,415		$ 589		4,247		7,611	(962)			(61)		(9)
Beginning Balance (in shares) at Dec. 31, 2015			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,039	859
Ending Balance at Sep. 30, 2016	14,267	11,793		$ 589		4,323		7,912	(962)			(61)		(8)
Ending Balance at Sep. 30, 2016	14,275		$ 33		5,830		9,557			$ (1,038)	(83)		(32)	(8)	8
Ending Balance (in shares) at Sep. 30, 2016			305,000,000	235,000,000						23,000,000
Beginning Balance at Mar. 31, 2016	13,201		$ 32		5,058		9,236			$ (1,038)	(61)		(34)		8
Beginning Balance at Mar. 31, 2016		11,562		$ 589		4,270		7,735	(962)			(61)		(9)
Beginning Balance (in shares) at Mar. 31, 2016			294,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	232	161					232	161
Common stock dividends	(204)	(186)					(204)	(186)
Issuance of common shares - public offering	702		$ 1		723						(22)
Issuance of common shares - public offering (in shares)			10,000,000
Issuance of common shares for stock plans, net of repurchases	26				26
Capital contribution by parent		28				28
Other comprehensive income	1	1											1	1
Ending Balance at Jun. 30, 2016		11,566		$ 589		4,298		7,710	(962)			(61)		(8)
Ending Balance at Jun. 30, 2016	13,958		$ 33		5,807		9,264			$ (1,038)	(83)		(33)	(8)	8
Ending Balance (in shares) at Jun. 30, 2016			304,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	497	388					497	388
Common stock dividends	(204)	(186)					(204)	(186)
Issuance of common shares for stock plans, net of repurchases	23				23
Issuance of common shares for stock plans, net of repurchases (in shares)			1,000,000
Capital contribution by parent		25				25
Other comprehensive income	1	0											1	0
Ending Balance at Sep. 30, 2016	14,267	$ 11,793		$ 589		$ 4,323		$ 7,912	$ (962)			$ (61)		(8)
Ending Balance at Sep. 30, 2016	$ 14,275		$ 33		$ 5,830		$ 9,557			$ (1,038)	$ (83)		$ (32)	$ (8)	$ 8
Ending Balance (in shares) at Sep. 30, 2016			305,000,000	235,000,000						23,000,000

General

General	9 Months Ended
	Sep. 30, 2016
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 Con Edison’s other utility subsidiary, Orange and Rockland Utilities, Inc. (O&R), Con Edison Transmission, Inc. (Con Edison Transmission) and Con Edison’s competitive energy businesses 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. The separate interim consolidated financial statements of each of the Companies are unaudited but, in the opinion of their respective managements, reflect all adjustments (which include only normally recurring adjustments) necessary for a fair presentation of the results for the interim periods presented. The Companies’ separate interim consolidated financial statements should be read together with their separate audited financial statements (including the combined notes thereto) included in Item 8 of their combined Annual Report on Form 10-K for the year ended December 31, 2015 and their separate unaudited financial statements (including the combined notes thereto) included in Part I, Item 1 of their combined Quarterly Report on Form 10-Q for the quarterly periods ended March 31, 2016 and June 30, 2016. Certain prior period amounts have been reclassified to conform to the current period presentation. 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 has the following competitive energy businesses: Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company which provides energy-related products and services to retail customers; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects. In addition, Con Edison has a subsidiary, Con Edison Transmission, that 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 P.
CECONY
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 Con Edison’s other utility subsidiary, Orange and Rockland Utilities, Inc. (O&R), Con Edison Transmission, Inc. (Con Edison Transmission) and Con Edison’s competitive energy businesses 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. The separate interim consolidated financial statements of each of the Companies are unaudited but, in the opinion of their respective managements, reflect all adjustments (which include only normally recurring adjustments) necessary for a fair presentation of the results for the interim periods presented. The Companies’ separate interim consolidated financial statements should be read together with their separate audited financial statements (including the combined notes thereto) included in Item 8 of their combined Annual Report on Form 10-K for the year ended December 31, 2015 and their separate unaudited financial statements (including the combined notes thereto) included in Part I, Item 1 of their combined Quarterly Report on Form 10-Q for the quarterly periods ended March 31, 2016 and June 30, 2016. Certain prior period amounts have been reclassified to conform to the current period presentation. 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 has the following competitive energy businesses: Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company which provides energy-related products and services to retail customers; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects. In addition, Con Edison has a subsidiary, Con Edison Transmission, that 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 P.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Earnings Per Common Share For the three and nine months ended September 30, 2016 and 2015 , basic and diluted earnings per share (EPS) for Con Edison are calculated as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, (Millions of Dollars, except per share amounts/Shares in Millions) 2016 2015 2016 2015 Net income $497 $428 $1,039 $1,017 Weighted average common shares outstanding – basic 304.5 292.9 299.1 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.4 1.3 1.4 1.3 Adjusted weighted average common shares outstanding – diluted 305.9 294.2 300.5 294.2 Net income per common share – basic $1.63 $1.46 $3.47 $3.47 Net income per common share – diluted $1.62 $1.45 $3.46 $3.46 Changes in Accumulated Other Comprehensive Income/(Loss) by Component For the three and nine months ended September 30, 2016 and 2015 , changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(33) $(39) $(8) $(10) Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 1 — 1 Current period OCI, net of taxes 1 1 — 1 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(2) and $(3) for Con Edison in 2016 and 2015 (a)(b) 3 4 1 2 Current period OCI, net of taxes 2 7 1 2 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) (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 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.
CECONY
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Earnings Per Common Share For the three and nine months ended September 30, 2016 and 2015 , basic and diluted earnings per share (EPS) for Con Edison are calculated as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, (Millions of Dollars, except per share amounts/Shares in Millions) 2016 2015 2016 2015 Net income $497 $428 $1,039 $1,017 Weighted average common shares outstanding – basic 304.5 292.9 299.1 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.4 1.3 1.4 1.3 Adjusted weighted average common shares outstanding – diluted 305.9 294.2 300.5 294.2 Net income per common share – basic $1.63 $1.46 $3.47 $3.47 Net income per common share – diluted $1.62 $1.45 $3.46 $3.46 Changes in Accumulated Other Comprehensive Income/(Loss) by Component For the three and nine months ended September 30, 2016 and 2015 , changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(33) $(39) $(8) $(10) Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 1 — 1 Current period OCI, net of taxes 1 1 — 1 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(2) and $(3) for Con Edison in 2016 and 2015 (a)(b) 3 4 1 2 Current period OCI, net of taxes 2 7 1 2 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) (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 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.

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2016
Public Utilities, General Disclosures [Line Items]
Regulatory Matters	Regulatory Matters Rate Plans CECONY - Electric In September 2016, CECONY, the staff of the New York State Public Service Commission (NYSPSC) and other parties entered into a Joint Proposal for a CECONY electric rate plan for the three -year period January 2017 through December 2019. The Joint Proposal is subject to NYSPSC approval. The following table contains a summary of the electric rate plan. Effective period January 2017 - December 2019 Base rate changes (a) Yr. 1 - $195 million Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $84 million Other revenue sources Retention of $75 million of annual transmission congestion revenues. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Yr. 1 - $376 million; Yr. 2 - $383 million; and Yr. 3 - $395 million. Cost reconciliations Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes(b), municipal infrastructure support costs(c), 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: Average rate base Yr. 1 - $18,902 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The electric base rate increases shown above are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. At the NYSPSC’s option, these increases may be implemented with increases of $199 million in each rate year. (b) 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. (c) 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. (d) 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. I n April 2016, the Federal Energy Regulatory Commission (FERC) rejected CECONY’s challenge to FERC’s approval of substantially increased charges allocated to CECONY for transmission service provided pursuant to the open access tariff of PJM Interconnection LLC (PJM). CECONY will continue to challenge FERC’s approval of the increased charges that will be incurred over the remaining contract term, and in May 2016 filed an appeal of FERC's decision with the U.S. Court of Appeals. In April 2016, CECONY notified PJM that it will not be exercising its option to continue the service beyond April 2017. CECONY - Gas In September 2016, CECONY, the staff of the NYSPSC and other parties entered into a Joint Proposal for a CECONY gas rate plan for the three -year period January 2017 through December 2019. The Joint Proposal is subject to NYSPSC approval. The following table contains a summary of the gas rate plan. Effective period January 2017 - December 2019 Base rate changes Yr. 1 - $(5) million(a) Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $39 million Other revenue sources Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $68 million; Yr. 2 - $75 million; and Yr. 3 - $83 million. Cost reconciliations 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.(b) Net utility plant reconciliations Target levels reflected in rates: Average rate base Yr. 1 - $4,841 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. (b) See footnotes (b), (c) and (d) to the table under “CECONY-Electric,” above. Rockland Electric Company (RECO) In April 2016, RECO filed a request with the New Jersey Board of Public Utilities for an electric rate increase of $10 million , effective March 2017. The filing reflected a return on common equity of 10.20 percent and a common equity ratio of 49.81 percent . In October 2016, RECO filed an update to its April 2016 request. The company decreased its requested March 2017 rate increase by $4 million to $6 million . The updated filing reflects a return on common equity of 10.20 percent and a common equity ratio of 50.15 percent . The filing reflects continuation of provisions pursuant to which the company recovers its purchased power and fuel costs from customers. Other Regulatory Matters In April 2016, the NYSPSC approved the September 2015 Joint Proposal among CECONY, the NYSPSC staff and others with respect to the prudence proceeding the NYSPSC commenced in February 2009 and related matters. Pursuant to the Joint Proposal, the company is required to credit $116 million to customers and, for the period 2017 through 2044, to not seek to recover from customers an aggregate $55 million relating to return on its capital expenditures. In addition, the company’s revenues that were made subject to potential refund in this proceeding are no longer subject to refund. At September 30, 2016 , the company had a $96 million regulatory liability for the remaining amount to be credited to customers related to this matter. In June 2014, the NYSPSC initiated a proceeding to investigate the practices of qualifying persons to perform plastic fusions on gas facilities. New York State regulations require gas utilities to qualify and, except in certain circumstances, annually requalify workers that perform fusion to join plastic pipe. The NYSPSC directed the New York gas utilities to provide information in this proceeding about their compliance with the qualification and requalification requirements and related matters; their procedures for compliance with all gas safety regulations; and their annual chief executive officer certifications regarding these and other procedures. CECONY’s qualification and requalification procedures had not included certain required testing to evaluate specimen fuses. In addition, CECONY and O&R had not timely requalified certain workers that had been qualified under their respective procedures to perform fusion to join plastic pipe. CECONY and O&R have requalified their workers who perform plastic pipe fusions. In May 2015, the NYSPSC, which indicated that it would address enforcement at a later date, ordered CECONY, O&R and other gas utilities to perform risk assessment and remediation plans, additional leakage surveying and reporting; CECONY to hire an independent statistician to develop a risk assessment and remediation plan; and the gas utilities to implement certain new plastic fusion requirements. In December 2015, the NYSPSC staff informed O&R that the company had satisfactorily completed its risk assessment and remediation plan. CECONY submitted its risk assessment and remediation plan to the NYSPSC staff in October 2016. In November 2015, the NYSPSC ordered CECONY to show cause why the NYSPSC should not commence proceedings to penalize the company for alleged violations of gas safety regulations identified by the NYSPSC staff in its investigation of a March 2014 explosion and fire and to review the prudence of the company's conduct associated with the incident. See "Manhattan Explosion and Fire" in Note H. In December 2015, the company responded that the NYSPSC should not institute the proceedings and disputed the alleged violations. At September 30, 2016 , CECONY had a $28 million regulatory liability related to the June 2014 plastic fusion proceeding and the November 2015 order to show cause. The company is unable to estimate the amount or range of its possible loss related to these matters in excess of this regulatory liability. CECONY has incurred costs for gas emergency response activities in 2014, 2015 and 2016 in excess of amounts reflected in the company’s gas rate plan. The company has requested NYSPSC authorization to defer as a regulatory asset $29 million and $35 million of such incremental costs incurred in 2014 and 2015, respectively. The company estimates that it will incur $37 million of such incremental costs in 2016. At September 30, 2016, the company had not deferred any such incremental costs. Regulatory Assets and Liabilities Regulatory assets and liabilities at September 30, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,369 $3,876 $3,220 $3,697 Future income tax 2,429 2,350 2,312 2,232 Environmental remediation costs 823 904 720 800 Revenue taxes 298 253 283 240 Deferred storm costs 89 185 30 110 Deferred derivative losses 55 50 49 46 Unamortized loss on reacquired debt 45 50 43 48 Surcharge for New York State assessment 43 44 40 40 O&R property tax reconciliation 39 46 — — Pension and other postretirement benefits deferrals 34 45 3 16 Net electric deferrals 29 44 29 44 Preferred stock redemption 25 26 25 26 O&R transition bond charges 16 21 — — Workers’ compensation 15 11 15 11 Recoverable energy costs 7 16 5 15 Other 228 175 212 157 Regulatory assets – noncurrent 7,544 8,096 6,986 7,482 Deferred derivative losses 94 113 87 103 Recoverable energy costs 25 19 24 18 Regulatory assets – current 119 132 111 121 Total Regulatory Assets $7,663 $8,228 $7,097 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $713 $676 $602 $570 Property tax reconciliation 205 303 205 303 Pension and other postretirement benefit deferrals 163 76 130 46 Net unbilled revenue deferrals 121 109 121 109 Prudence proceeding 96 99 96 99 Unrecognized other postretirement costs 91 28 91 28 New York State income tax rate change 66 75 64 72 Base rate change deferrals 62 128 62 128 Variable-rate tax-exempt debt – cost rate reconciliation 60 70 52 60 Carrying charges on repair allowance and bonus depreciation 57 49 56 48 Earnings sharing - electric, gas and steam 34 80 26 80 Net utility plant reconciliations 27 32 27 31 Property tax refunds 12 44 12 44 World Trade Center settlement proceeds 5 21 5 21 Other 208 187 176 150 Regulatory liabilities – noncurrent 1,920 1,977 1,725 1,789 Revenue decoupling mechanism 74 45 70 45 Refundable energy costs 37 64 18 33 Deferred derivative gains 12 6 8 6 Regulatory liabilities – current 123 115 96 84 Total Regulatory Liabilities $2,043 $2,092 $1,821 $1,873
CECONY
Public Utilities, General Disclosures [Line Items]
Regulatory Matters	Regulatory Matters Rate Plans CECONY - Electric In September 2016, CECONY, the staff of the New York State Public Service Commission (NYSPSC) and other parties entered into a Joint Proposal for a CECONY electric rate plan for the three -year period January 2017 through December 2019. The Joint Proposal is subject to NYSPSC approval. The following table contains a summary of the electric rate plan. Effective period January 2017 - December 2019 Base rate changes (a) Yr. 1 - $195 million Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $84 million Other revenue sources Retention of $75 million of annual transmission congestion revenues. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Yr. 1 - $376 million; Yr. 2 - $383 million; and Yr. 3 - $395 million. Cost reconciliations Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes(b), municipal infrastructure support costs(c), 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: Average rate base Yr. 1 - $18,902 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The electric base rate increases shown above are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. At the NYSPSC’s option, these increases may be implemented with increases of $199 million in each rate year. (b) 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. (c) 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. (d) 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. I n April 2016, the Federal Energy Regulatory Commission (FERC) rejected CECONY’s challenge to FERC’s approval of substantially increased charges allocated to CECONY for transmission service provided pursuant to the open access tariff of PJM Interconnection LLC (PJM). CECONY will continue to challenge FERC’s approval of the increased charges that will be incurred over the remaining contract term, and in May 2016 filed an appeal of FERC's decision with the U.S. Court of Appeals. In April 2016, CECONY notified PJM that it will not be exercising its option to continue the service beyond April 2017. CECONY - Gas In September 2016, CECONY, the staff of the NYSPSC and other parties entered into a Joint Proposal for a CECONY gas rate plan for the three -year period January 2017 through December 2019. The Joint Proposal is subject to NYSPSC approval. The following table contains a summary of the gas rate plan. Effective period January 2017 - December 2019 Base rate changes Yr. 1 - $(5) million(a) Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $39 million Other revenue sources Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $68 million; Yr. 2 - $75 million; and Yr. 3 - $83 million. Cost reconciliations 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.(b) Net utility plant reconciliations Target levels reflected in rates: Average rate base Yr. 1 - $4,841 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. (b) See footnotes (b), (c) and (d) to the table under “CECONY-Electric,” above. Rockland Electric Company (RECO) In April 2016, RECO filed a request with the New Jersey Board of Public Utilities for an electric rate increase of $10 million , effective March 2017. The filing reflected a return on common equity of 10.20 percent and a common equity ratio of 49.81 percent . In October 2016, RECO filed an update to its April 2016 request. The company decreased its requested March 2017 rate increase by $4 million to $6 million . The updated filing reflects a return on common equity of 10.20 percent and a common equity ratio of 50.15 percent . The filing reflects continuation of provisions pursuant to which the company recovers its purchased power and fuel costs from customers. Other Regulatory Matters In April 2016, the NYSPSC approved the September 2015 Joint Proposal among CECONY, the NYSPSC staff and others with respect to the prudence proceeding the NYSPSC commenced in February 2009 and related matters. Pursuant to the Joint Proposal, the company is required to credit $116 million to customers and, for the period 2017 through 2044, to not seek to recover from customers an aggregate $55 million relating to return on its capital expenditures. In addition, the company’s revenues that were made subject to potential refund in this proceeding are no longer subject to refund. At September 30, 2016 , the company had a $96 million regulatory liability for the remaining amount to be credited to customers related to this matter. In June 2014, the NYSPSC initiated a proceeding to investigate the practices of qualifying persons to perform plastic fusions on gas facilities. New York State regulations require gas utilities to qualify and, except in certain circumstances, annually requalify workers that perform fusion to join plastic pipe. The NYSPSC directed the New York gas utilities to provide information in this proceeding about their compliance with the qualification and requalification requirements and related matters; their procedures for compliance with all gas safety regulations; and their annual chief executive officer certifications regarding these and other procedures. CECONY’s qualification and requalification procedures had not included certain required testing to evaluate specimen fuses. In addition, CECONY and O&R had not timely requalified certain workers that had been qualified under their respective procedures to perform fusion to join plastic pipe. CECONY and O&R have requalified their workers who perform plastic pipe fusions. In May 2015, the NYSPSC, which indicated that it would address enforcement at a later date, ordered CECONY, O&R and other gas utilities to perform risk assessment and remediation plans, additional leakage surveying and reporting; CECONY to hire an independent statistician to develop a risk assessment and remediation plan; and the gas utilities to implement certain new plastic fusion requirements. In December 2015, the NYSPSC staff informed O&R that the company had satisfactorily completed its risk assessment and remediation plan. CECONY submitted its risk assessment and remediation plan to the NYSPSC staff in October 2016. In November 2015, the NYSPSC ordered CECONY to show cause why the NYSPSC should not commence proceedings to penalize the company for alleged violations of gas safety regulations identified by the NYSPSC staff in its investigation of a March 2014 explosion and fire and to review the prudence of the company's conduct associated with the incident. See "Manhattan Explosion and Fire" in Note H. In December 2015, the company responded that the NYSPSC should not institute the proceedings and disputed the alleged violations. At September 30, 2016 , CECONY had a $28 million regulatory liability related to the June 2014 plastic fusion proceeding and the November 2015 order to show cause. The company is unable to estimate the amount or range of its possible loss related to these matters in excess of this regulatory liability. CECONY has incurred costs for gas emergency response activities in 2014, 2015 and 2016 in excess of amounts reflected in the company’s gas rate plan. The company has requested NYSPSC authorization to defer as a regulatory asset $29 million and $35 million of such incremental costs incurred in 2014 and 2015, respectively. The company estimates that it will incur $37 million of such incremental costs in 2016. At September 30, 2016, the company had not deferred any such incremental costs. Regulatory Assets and Liabilities Regulatory assets and liabilities at September 30, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,369 $3,876 $3,220 $3,697 Future income tax 2,429 2,350 2,312 2,232 Environmental remediation costs 823 904 720 800 Revenue taxes 298 253 283 240 Deferred storm costs 89 185 30 110 Deferred derivative losses 55 50 49 46 Unamortized loss on reacquired debt 45 50 43 48 Surcharge for New York State assessment 43 44 40 40 O&R property tax reconciliation 39 46 — — Pension and other postretirement benefits deferrals 34 45 3 16 Net electric deferrals 29 44 29 44 Preferred stock redemption 25 26 25 26 O&R transition bond charges 16 21 — — Workers’ compensation 15 11 15 11 Recoverable energy costs 7 16 5 15 Other 228 175 212 157 Regulatory assets – noncurrent 7,544 8,096 6,986 7,482 Deferred derivative losses 94 113 87 103 Recoverable energy costs 25 19 24 18 Regulatory assets – current 119 132 111 121 Total Regulatory Assets $7,663 $8,228 $7,097 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $713 $676 $602 $570 Property tax reconciliation 205 303 205 303 Pension and other postretirement benefit deferrals 163 76 130 46 Net unbilled revenue deferrals 121 109 121 109 Prudence proceeding 96 99 96 99 Unrecognized other postretirement costs 91 28 91 28 New York State income tax rate change 66 75 64 72 Base rate change deferrals 62 128 62 128 Variable-rate tax-exempt debt – cost rate reconciliation 60 70 52 60 Carrying charges on repair allowance and bonus depreciation 57 49 56 48 Earnings sharing - electric, gas and steam 34 80 26 80 Net utility plant reconciliations 27 32 27 31 Property tax refunds 12 44 12 44 World Trade Center settlement proceeds 5 21 5 21 Other 208 187 176 150 Regulatory liabilities – noncurrent 1,920 1,977 1,725 1,789 Revenue decoupling mechanism 74 45 70 45 Refundable energy costs 37 64 18 33 Deferred derivative gains 12 6 8 6 Regulatory liabilities – current 123 115 96 84 Total Regulatory Liabilities $2,043 $2,092 $1,821 $1,873

Capitalization

Capitalization	9 Months Ended
	Sep. 30, 2016
Debt Instrument [Line Items]
Capitalization	Capitalization In February 2016, a Con Edison Development subsidiary issued $218 million aggregate principal amount of 4.21 percent senior notes, due 2041 , secured by the company's Texas Solar 7 solar project. In May 2016, Con Edison issued approximately 10 million common shares resulting in net proceeds, after issuance expenses, of $702 million , and $500 million aggregate principal amount of 2.00 percent debentures, due 2021 . Also, in May 2016, a Con Edison Development subsidiary issued $95 million aggregate principal amount of 4.07 percent senior notes, due 2036 , secured by the company's California Holding 3 solar projects. In June 2016, Con Edison borrowed $400 million pursuant to a credit agreement with a syndicate of banks. The borrowing matures in 2018 and bears interest at a LIBOR plus margin of 1.00 percent. Also in June 2016, CECONY issued $550 million aggregate principal amount of 3.85 percent debentures, due 2046 . Also, in June 2016, a Con Edison Solutions subsidiary borrowed $2 million pursuant to a loan agreement with a New Jersey utility. The borrowing matures in 2026 , bears interest of 11.18 percent and may be repaid in cash or project Solar Renewable Energy Certificates. In September 2016, CECONY redeemed at maturity $400 million aggregate principal amount of 5.50 percent debentures. In September 2016, O&R agreed to issue and sell for delivery in December 2016 $75 million aggregate principal amount of 3.88 percent debentures, due 2046. In October 2016, O&R redeemed at maturity $75 million aggregate principal amount of 5.45 percent debentures. The carrying amounts and fair values of long-term debt at September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $14,093 $16,325 $12,745 $13,856 CECONY $11,584 $13,564 $11,437 $12,427 Fair values of long-term debt have been estimated primarily using available market information. For Con Edison, $15,689 million and $636 million of the fair value of long-term debt at September 30, 2016 are classified as Level 2 and Level 3, respectively. For CECONY, $12,928 million and $636 million of the fair value of long-term debt at September 30, 2016 are classified as Level 2 and Level 3, respectively (see Note L). The $636 million of long-term debt classified as Level 3 is CECONY’s tax-exempt, auction-rate securities for which the market is highly illiquid and there is a lack of observable inputs.
CECONY
Debt Instrument [Line Items]
Capitalization	Capitalization In February 2016, a Con Edison Development subsidiary issued $218 million aggregate principal amount of 4.21 percent senior notes, due 2041 , secured by the company's Texas Solar 7 solar project. In May 2016, Con Edison issued approximately 10 million common shares resulting in net proceeds, after issuance expenses, of $702 million , and $500 million aggregate principal amount of 2.00 percent debentures, due 2021 . Also, in May 2016, a Con Edison Development subsidiary issued $95 million aggregate principal amount of 4.07 percent senior notes, due 2036 , secured by the company's California Holding 3 solar projects. In June 2016, Con Edison borrowed $400 million pursuant to a credit agreement with a syndicate of banks. The borrowing matures in 2018 and bears interest at a LIBOR plus margin of 1.00 percent. Also in June 2016, CECONY issued $550 million aggregate principal amount of 3.85 percent debentures, due 2046 . Also, in June 2016, a Con Edison Solutions subsidiary borrowed $2 million pursuant to a loan agreement with a New Jersey utility. The borrowing matures in 2026 , bears interest of 11.18 percent and may be repaid in cash or project Solar Renewable Energy Certificates. In September 2016, CECONY redeemed at maturity $400 million aggregate principal amount of 5.50 percent debentures. In September 2016, O&R agreed to issue and sell for delivery in December 2016 $75 million aggregate principal amount of 3.88 percent debentures, due 2046. In October 2016, O&R redeemed at maturity $75 million aggregate principal amount of 5.45 percent debentures. The carrying amounts and fair values of long-term debt at September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $14,093 $16,325 $12,745 $13,856 CECONY $11,584 $13,564 $11,437 $12,427 Fair values of long-term debt have been estimated primarily using available market information. For Con Edison, $15,689 million and $636 million of the fair value of long-term debt at September 30, 2016 are classified as Level 2 and Level 3, respectively. For CECONY, $12,928 million and $636 million of the fair value of long-term debt at September 30, 2016 are classified as Level 2 and Level 3, respectively (see Note L). The $636 million of long-term debt classified as Level 3 is CECONY’s tax-exempt, auction-rate securities for which the market is highly illiquid and there is a lack of observable inputs.

Short-Term Borrowing

Short-Term Borrowing	9 Months Ended
	Sep. 30, 2016
Short-Term Borrowing	Short-Term Borrowing At September 30, 2016 , Con Edison had $601 million of commercial paper outstanding of which $480 million was outstanding under CECONY’s program. The weighted average interest rate at September 30, 2016 was 0.7 percent for both Con Edison and CECONY. At December 31, 2015 , Con Edison had $1,529 million of commercial paper outstanding of which $1,033 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2015 was 0.7 percent for both Con Edison and CECONY. At September 30, 2016 and December 31, 2015 , no loans were outstanding under the credit agreement (Credit Agreement) and $2 million (including $2 million for CECONY) and $15 million of letters of credit were outstanding under the Credit Agreement, respectively.
CECONY
Short-Term Borrowing	Short-Term Borrowing At September 30, 2016 , Con Edison had $601 million of commercial paper outstanding of which $480 million was outstanding under CECONY’s program. The weighted average interest rate at September 30, 2016 was 0.7 percent for both Con Edison and CECONY. At December 31, 2015 , Con Edison had $1,529 million of commercial paper outstanding of which $1,033 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2015 was 0.7 percent for both Con Edison and CECONY. At September 30, 2016 and December 31, 2015 , no loans were outstanding under the credit agreement (Credit Agreement) and $2 million (including $2 million for CECONY) and $15 million of letters of credit were outstanding under the Credit Agreement, respectively.

Pension Benefits

Pension Benefits	9 Months Ended
	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Pension Benefits	Pension Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — NET PERIODIC BENEFIT COST $131 $191 $121 $178 Amortization of regulatory asset — 1 — 1 TOTAL PERIODIC BENEFIT COST $131 $192 $121 $179 Cost capitalized (51) (80) (49) (76) Reconciliation to rate level 10 (14) 13 (14) Cost charged to operating expenses $90 $98 $85 $89 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $207 $223 $194 $209 Interest cost on projected benefit obligation 447 431 419 404 Expected return on plan assets (711) (664) (674) (630) Recognition of net actuarial loss 447 581 424 550 Recognition of prior service costs 3 3 1 1 NET PERIODIC BENEFIT COST $393 $574 $364 $534 Amortization of regulatory asset — 2 — 2 TOTAL PERIODIC BENEFIT COST $393 $576 $364 $536 Cost capitalized (157) (224) (148) (214) Reconciliation to rate level 35 (56) 39 (56) Cost charged to operating expenses $271 $296 $255 $266 Expected Contributions Based on estimates as of September 30, 2016 , the Companies expect to make contributions to the pension plans during 2016 of $508 million (of which $469 million is to be contributed 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. During the first nine months of 2016 , the Companies contributed $504 million (of which $466 million was contributed by CECONY) to the pension plans. CECONY also contributed $17 million to its external trust for supplemental plans.
CECONY
Defined Benefit Plan Disclosure [Line Items]
Pension Benefits	Pension Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — NET PERIODIC BENEFIT COST $131 $191 $121 $178 Amortization of regulatory asset — 1 — 1 TOTAL PERIODIC BENEFIT COST $131 $192 $121 $179 Cost capitalized (51) (80) (49) (76) Reconciliation to rate level 10 (14) 13 (14) Cost charged to operating expenses $90 $98 $85 $89 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $207 $223 $194 $209 Interest cost on projected benefit obligation 447 431 419 404 Expected return on plan assets (711) (664) (674) (630) Recognition of net actuarial loss 447 581 424 550 Recognition of prior service costs 3 3 1 1 NET PERIODIC BENEFIT COST $393 $574 $364 $534 Amortization of regulatory asset — 2 — 2 TOTAL PERIODIC BENEFIT COST $393 $576 $364 $536 Cost capitalized (157) (224) (148) (214) Reconciliation to rate level 35 (56) 39 (56) Cost charged to operating expenses $271 $296 $255 $266 Expected Contributions Based on estimates as of September 30, 2016 , the Companies expect to make contributions to the pension plans during 2016 of $508 million (of which $469 million is to be contributed 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. During the first nine months of 2016 , the Companies contributed $504 million (of which $466 million was contributed by CECONY) to the pension plans. CECONY also contributed $17 million to its external trust for supplemental plans.

Other Postretirement Benefits

Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Other Postretirement Benefits	Other Postretirement Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic other postretirement benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (3) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(6) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 6 2 Cost charged to operating expenses $2 $4 $2 $2 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $13 $15 $10 $11 Interest cost on accumulated other postretirement benefit obligation 36 38 30 32 Expected return on plan assets (58) (59) (50) (51) Recognition of net actuarial loss 4 24 2 21 Recognition of prior service cost (15) (15) (11) (10) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(20) $3 $(19) $3 Cost capitalized 5 (2) 5 (2) Reconciliation to rate level 20 12 19 5 Cost charged to operating expenses $5 $13 $5 $6 Contributions During the first nine months of 2016, the Companies contributed $6 million , nearly all of which was contributed by CECONY, to the other postretirement benefit plans. The Companies' policy is to fund the total periodic benefit cost of the plans to the extent tax deductible.
CECONY
Defined Benefit Plan Disclosure [Line Items]
Other Postretirement Benefits	Other Postretirement Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic other postretirement benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (3) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(6) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 6 2 Cost charged to operating expenses $2 $4 $2 $2 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $13 $15 $10 $11 Interest cost on accumulated other postretirement benefit obligation 36 38 30 32 Expected return on plan assets (58) (59) (50) (51) Recognition of net actuarial loss 4 24 2 21 Recognition of prior service cost (15) (15) (11) (10) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(20) $3 $(19) $3 Cost capitalized 5 (2) 5 (2) Reconciliation to rate level 20 12 19 5 Cost charged to operating expenses $5 $13 $5 $6 Contributions During the first nine months of 2016, the Companies contributed $6 million , nearly all of which was contributed by CECONY, to the other postretirement benefit plans. The Companies' policy is to fund the total periodic benefit cost of the plans to the extent tax deductible.

Environmental Matters

Environmental Matters	9 Months Ended
	Sep. 30, 2016
Site Contingency [Line Items]
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 September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $664 $679 $574 $579 Other Superfund Sites 88 86 87 86 Total $752 $765 $661 $665 Regulatory assets $823 $904 $720 $800 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 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. Under their current rate plans, the Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) certain site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $8 $6 $5 $6 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $20 $21 $10 $18 Con Edison and CECONY received $1 million in insurance recoveries for the three and nine months ended September 30, 2016 . No insurance recoveries were received by Con Edison or CECONY for the three and nine months ended September 30, 2015 . In 2015, 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 $2.7 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 September 30, 2016 , Con Edison and CECONY had 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. The estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Trial courts have begun, and unless otherwise determined by an appellate court may continue, to apply a different standard 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. Under its current rate plans, 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 September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $90 $86 $85 $81 Regulatory assets – workers’ compensation $15 $11 $15 $11
CECONY
Site Contingency [Line Items]
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 September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $664 $679 $574 $579 Other Superfund Sites 88 86 87 86 Total $752 $765 $661 $665 Regulatory assets $823 $904 $720 $800 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 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. Under their current rate plans, the Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) certain site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $8 $6 $5 $6 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $20 $21 $10 $18 Con Edison and CECONY received $1 million in insurance recoveries for the three and nine months ended September 30, 2016 . No insurance recoveries were received by Con Edison or CECONY for the three and nine months ended September 30, 2015 . In 2015, 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 $2.7 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 September 30, 2016 , Con Edison and CECONY had 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. The estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Trial courts have begun, and unless otherwise determined by an appellate court may continue, to apply a different standard 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. Under its current rate plans, 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 September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $90 $86 $85 $81 Regulatory assets – workers’ compensation $15 $11 $15 $11

Other Material Contingencies

Other Material Contingencies	9 Months Ended
	Sep. 30, 2016
Guarantor Obligations [Line Items]
Other Material Contingencies	Other Material Contingencies Manhattan Steam Main Rupture In July 2007, a CECONY steam main located in midtown Manhattan ruptured. It has been reported that one person died and others were injured as a result of the incident. Several buildings in the area were damaged. Debris from the incident included dirt and mud containing asbestos. The response to the incident required the closing of several buildings and streets for various periods. Approximately sixty suits are pending against the company seeking generally unspecified compensatory 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 to satisfy its liability to others in connection with the suits. In the company’s estimation, there is not a reasonable possibility that an exposure to loss exists for the suits that is materially in excess of the estimated liability accrued. At September 30, 2016 , the company has accrued its estimated liability for the suits of $30 million and an insurance receivable of $39 million . Manhattan Explosion and Fire On March 12, 2014, two multi-use five-story tall buildings located on Park Avenue between 116 th and 117 th Street 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 (which also conducted an investigation). 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. Approximately seventy 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 September 30, 2016 , the company had not accrued a liability for damages related to the incident. Other Contingencies See “Other Regulatory Matters” in Note B and “Uncertain Tax Positions” in Note I. Guarantees Con Edison and its subsidiaries enter into various agreements providing financial or performance assurance primarily to third parties on behalf of their subsidiaries. Maximum amounts guaranteed by Con Edison totaled $2,422 million and $2,856 million at September 30, 2016 and December 31, 2015 , respectively. A summary, by type and term, of Con Edison’s total guarantees at September 30, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $618 $430 $— $1,048 Energy transactions 635 57 91 783 Renewable electric production projects 445 — 18 463 Other 128 — — 128 Total $1,826 $487 $109 $2,422 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. NY Transco’s transmission projects are expected to be initially developed by CECONY and other New York transmission owners and then transferred to NY Transco. In May 2016, the transmission owners transferred certain projects to NY Transco, as to which CET Electric made its required contributions. The other projects that were proposed when NY Transco was formed remain 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 timing of the contributions is not certain. Also included within the table above is a guarantee for $25 million from Con Edison on behalf of CET Gas in relation to a proposed gas transmission project in West Virginia and Virginia. See Note P. Energy Transactions — Con Edison guarantees payments on behalf of its competitive 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. Guarantee amounts shown above include $123 million of guarantees or other credit support provided by Con Edison on behalf of Con Edison Solutions that may continue in effect during the period in which Con Edison Solutions provides transition services in connection with the retail electric supply business it sold in September 2016. See Note P. As part of the sale agreement, the purchaser has agreed to pay Con Edison Solutions for draws on such guarantees or other credit support. Renewable Electric Production Projects — Con Edison, Con Edison Development, and Con Edison Solutions guarantee payments associated with the investment in solar and wind energy facilities on behalf of their wholly-owned subsidiaries. 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 energy service projects and operation of solar energy facilities of Con Edison Solutions and Con Edison Development, respectively. Other guarantees also includes Con Edison's guarantee (subject to a $53 million maximum amount) of certain obligations of Con Edison Solutions under its agreement to sell its retail electric supply business. See Note P. In addition, Con Edison issued a guarantee estimated at $5 million to the Public Utility Commission of Texas covering obligations of Con Edison Solutions as a retail electric provider. As part of the sale agreement for the retail electric supply business discussed above, the purchaser has agreed to pay Con Edison Solutions for draws on the guarantee to the Public Utility Commission of Texas.
CECONY
Guarantor Obligations [Line Items]
Other Material Contingencies	Other Material Contingencies Manhattan Steam Main Rupture In July 2007, a CECONY steam main located in midtown Manhattan ruptured. It has been reported that one person died and others were injured as a result of the incident. Several buildings in the area were damaged. Debris from the incident included dirt and mud containing asbestos. The response to the incident required the closing of several buildings and streets for various periods. Approximately sixty suits are pending against the company seeking generally unspecified compensatory 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 to satisfy its liability to others in connection with the suits. In the company’s estimation, there is not a reasonable possibility that an exposure to loss exists for the suits that is materially in excess of the estimated liability accrued. At September 30, 2016 , the company has accrued its estimated liability for the suits of $30 million and an insurance receivable of $39 million . Manhattan Explosion and Fire On March 12, 2014, two multi-use five-story tall buildings located on Park Avenue between 116 th and 117 th Street 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 (which also conducted an investigation). 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. Approximately seventy 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 September 30, 2016 , the company had not accrued a liability for damages related to the incident. Other Contingencies See “Other Regulatory Matters” in Note B and “Uncertain Tax Positions” in Note I. Guarantees Con Edison and its subsidiaries enter into various agreements providing financial or performance assurance primarily to third parties on behalf of their subsidiaries. Maximum amounts guaranteed by Con Edison totaled $2,422 million and $2,856 million at September 30, 2016 and December 31, 2015 , respectively. A summary, by type and term, of Con Edison’s total guarantees at September 30, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $618 $430 $— $1,048 Energy transactions 635 57 91 783 Renewable electric production projects 445 — 18 463 Other 128 — — 128 Total $1,826 $487 $109 $2,422 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. NY Transco’s transmission projects are expected to be initially developed by CECONY and other New York transmission owners and then transferred to NY Transco. In May 2016, the transmission owners transferred certain projects to NY Transco, as to which CET Electric made its required contributions. The other projects that were proposed when NY Transco was formed remain 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 timing of the contributions is not certain. Also included within the table above is a guarantee for $25 million from Con Edison on behalf of CET Gas in relation to a proposed gas transmission project in West Virginia and Virginia. See Note P. Energy Transactions — Con Edison guarantees payments on behalf of its competitive 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. Guarantee amounts shown above include $123 million of guarantees or other credit support provided by Con Edison on behalf of Con Edison Solutions that may continue in effect during the period in which Con Edison Solutions provides transition services in connection with the retail electric supply business it sold in September 2016. See Note P. As part of the sale agreement, the purchaser has agreed to pay Con Edison Solutions for draws on such guarantees or other credit support. Renewable Electric Production Projects — Con Edison, Con Edison Development, and Con Edison Solutions guarantee payments associated with the investment in solar and wind energy facilities on behalf of their wholly-owned subsidiaries. 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 energy service projects and operation of solar energy facilities of Con Edison Solutions and Con Edison Development, respectively. Other guarantees also includes Con Edison's guarantee (subject to a $53 million maximum amount) of certain obligations of Con Edison Solutions under its agreement to sell its retail electric supply business. See Note P. In addition, Con Edison issued a guarantee estimated at $5 million to the Public Utility Commission of Texas covering obligations of Con Edison Solutions as a retail electric provider. As part of the sale agreement for the retail electric supply business discussed above, the purchaser has agreed to pay Con Edison Solutions for draws on the guarantee to the Public Utility Commission of Texas.

Income Tax

Income Tax	9 Months Ended
	Sep. 30, 2016
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense increased to $314 million for the three months ended September 30, 2016 from $249 million for the three months ended September 30, 2015 . Con Edison's effective tax rate for the three months ended September 30, 2016 and 2015 was 39 percent and 37 percent, respectively. The increase in Con Edison's effective tax rate is primarily due to higher state income taxes and a decrease in tax benefits for plant-related flow through items, offset in part by higher tax benefits for injuries and damages payments, research and development tax credits and renewable energy tax credits. CECONY’s income tax expense increased to $226 million for the three months ended September 30, 2016 from $222 million for the three months ended September 30, 2015 . CECONY's effective tax rate for the three months ended September 30, 2016 and 2015 was 37 percent . The decrease in tax benefits for plant-related flow through items, were more than offset by lower state income taxes and increased tax benefits as a result of higher injuries and damages payments and research and development tax credits. Con Edison’s income tax expense increased to $602 million for the nine months ended September 30, 2016 from $548 million for the nine months ended September 30, 2015 . Con Edison's effective tax rate for the nine months ended September 30, 2016 and 2015 was 37 percent and 35 percent , respectively. The increase in Con Edison's effective tax rate is primarily due to higher state income taxes and a decrease in tax benefits for plant-related flow through items, offset in part by higher tax benefits for injuries and damages payments, research and development tax credits and renewable energy tax credits. CECONY’s income tax expense decreased to $491 million for the nine months ended September 30, 2016 from $515 million for the nine months ended September 30, 2015 . CECONY's effective tax rate for the nine months ended September 30, 2016 and 2015 was 36 percent and 35 percent , respectively. The increase in CECONY's effective tax rate is primarily related to a decrease in tax benefits for plant-related flow through items, offset in part by lower state income taxes and increased research and development tax credits. In September 2016, Con Edison filed its 2015 federal income tax return, requesting a refund of $19 million of estimated tax payments and, in October 2016, the company received the refund. The company carried back a 2015 net operating loss to 2007, requesting a refund of $16 million of federal income tax and, in October 2016, the company received the refund. Con Edison anticipates a federal net operating loss for 2016, primarily due to bonus depreciation. Con Edison expects to carryback a portion of its 2016 net operating loss and recover $32 million of income tax. General business tax credits that became available as a result of the net operating loss carryback, as well as the remaining 2016 net operating loss will be carried forward to future tax years. 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. Uncertain Tax Positions At September 30, 2016 , the estimated liability for uncertain tax positions for Con Edison was $37 million ( $5 million for CECONY). Con Edison reasonably expects to resolve approximately $29 million ( $20 million , net of federal taxes) of its uncertain tax positions within the next twelve months, of which the entire amount, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $5 million ( $4 million , net of federal taxes), of which the entire amount, if recognized, would reduce CECONY’s effective tax rate. The total amount of unrecognized tax benefits, if recognized, that would reduce Con Edison’s effective tax rate is $37 million ( $25 million , net of federal taxes). 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 the three and nine months ended September 30, 2016 , the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At September 30, 2016 and December 31, 2015 , the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.
CECONY
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense increased to $314 million for the three months ended September 30, 2016 from $249 million for the three months ended September 30, 2015 . Con Edison's effective tax rate for the three months ended September 30, 2016 and 2015 was 39 percent and 37 percent, respectively. The increase in Con Edison's effective tax rate is primarily due to higher state income taxes and a decrease in tax benefits for plant-related flow through items, offset in part by higher tax benefits for injuries and damages payments, research and development tax credits and renewable energy tax credits. CECONY’s income tax expense increased to $226 million for the three months ended September 30, 2016 from $222 million for the three months ended September 30, 2015 . CECONY's effective tax rate for the three months ended September 30, 2016 and 2015 was 37 percent . The decrease in tax benefits for plant-related flow through items, were more than offset by lower state income taxes and increased tax benefits as a result of higher injuries and damages payments and research and development tax credits. Con Edison’s income tax expense increased to $602 million for the nine months ended September 30, 2016 from $548 million for the nine months ended September 30, 2015 . Con Edison's effective tax rate for the nine months ended September 30, 2016 and 2015 was 37 percent and 35 percent , respectively. The increase in Con Edison's effective tax rate is primarily due to higher state income taxes and a decrease in tax benefits for plant-related flow through items, offset in part by higher tax benefits for injuries and damages payments, research and development tax credits and renewable energy tax credits. CECONY’s income tax expense decreased to $491 million for the nine months ended September 30, 2016 from $515 million for the nine months ended September 30, 2015 . CECONY's effective tax rate for the nine months ended September 30, 2016 and 2015 was 36 percent and 35 percent , respectively. The increase in CECONY's effective tax rate is primarily related to a decrease in tax benefits for plant-related flow through items, offset in part by lower state income taxes and increased research and development tax credits. In September 2016, Con Edison filed its 2015 federal income tax return, requesting a refund of $19 million of estimated tax payments and, in October 2016, the company received the refund. The company carried back a 2015 net operating loss to 2007, requesting a refund of $16 million of federal income tax and, in October 2016, the company received the refund. Con Edison anticipates a federal net operating loss for 2016, primarily due to bonus depreciation. Con Edison expects to carryback a portion of its 2016 net operating loss and recover $32 million of income tax. General business tax credits that became available as a result of the net operating loss carryback, as well as the remaining 2016 net operating loss will be carried forward to future tax years. 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. Uncertain Tax Positions At September 30, 2016 , the estimated liability for uncertain tax positions for Con Edison was $37 million ( $5 million for CECONY). Con Edison reasonably expects to resolve approximately $29 million ( $20 million , net of federal taxes) of its uncertain tax positions within the next twelve months, of which the entire amount, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $5 million ( $4 million , net of federal taxes), of which the entire amount, if recognized, would reduce CECONY’s effective tax rate. The total amount of unrecognized tax benefits, if recognized, that would reduce Con Edison’s effective tax rate is $37 million ( $25 million , net of federal taxes). 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 the three and nine months ended September 30, 2016 , the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At September 30, 2016 and December 31, 2015 , the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.

Financial Information by Busine

Financial Information by Business Segment	9 Months Ended
	Sep. 30, 2016
Segment Reporting Information [Line Items]
Financial Information by Business Segment	Financial Information by Business Segment Con Edison’s principal business segments prior to June 2016 were CECONY’s regulated utility activities, O&R’s regulated utility activities and Con Edison’s competitive energy businesses. CECONY’s principal business segments are its regulated electric, gas and steam utility activities. In 2016, Con Edison Transmission began investing, through CET Electric and CET Gas, in electric transmission and gas pipeline and storage assets (see Note P). As a result of these investments, in June 2016 Con Edison changed its business segments to add Con Edison Transmission as a separate reportable segment based on management’s reporting and decision-making, including performance evaluation and resource allocation. For comparison purposes, the previously reported financial information by business segments was reclassified to reflect the current business segment presentation. The financial data for the business segments are as follows: As of and for the Three Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $2,557 $2,558 $5 $4 $217 $207 $841 $811 $2 $(2) $117 $111 $275 $260 $30,580 $30,369 $411 $419 Gas 208 213 1 1 41 35 (28) (17) — (1) 27 24 (24) (17) 7,300 6,687 224 178 Steam 63 58 22 22 20 20 (47) (49) — — 10 10 (17) (18) 2,556 2,614 24 27 Consolidation adjustments — — (28) (27) — — — — — — — — — — — — — — Total CECONY $2,828 $2,829 $— $— $278 $262 $766 $745 $2 $(3) $154 $145 $234 $225 $40,436 $39,670 $659 $624 O&R Electric $213 $205 $— $— $12 $13 $55 $51 $1 $(4) $6 $6 $20 $17 $1,985 $1,959 $24 $26 Gas 27 24 — — 5 4 (7) (9) — (1) 3 3 (4) (5) 799 754 14 12 Total O&R $240 $229 $— $— $17 $17 $48 $42 $1 $(5) $9 $9 $16 $12 $2,784 $2,713 $38 $38 Competitive energy businesses $350 $386 $(2) $(2) $11 $6 $125 $43 $27 $17 $7 $2 $67 $21 $2,394 $1,547 $121 $212 Con Edison Transmission — — — — — — (1) — 20 — 3 — — — 1,072 2 — — Other (a) (1) (1) 2 2 (1) — 2 — (1) — 5 6 4 2 630 1,039 — — Total Con Edison $3,417 $3,443 $— $— $305 $285 $940 $830 $49 $9 $178 $162 $321 $260 $47,316 $44,971 $818 $874 (a) Parent company and consolidation adjustments. Other does not represent a business segment. As of and for the Nine Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $6,222 $6,416 $13 $13 $645 $610 $1,487 $1,511 $3 $(3) $342 $333 $412 $401 $30,580 $30,369 $1,133 $1,165 Gas 1,113 1,177 4 4 118 105 273 278 (1) (1) 79 71 73 82 7,300 6,687 589 466 Steam 406 529 65 65 62 58 39 100 — — 30 31 18 42 2,556 2,614 74 65 Consolidation adjustments — — (82) (82) — — — — — — — — — — — — — — Total CECONY $7,741 $8,122 $— $— $825 $773 $1,799 $1,889 $2 $(4) $451 $435 $503 $525 $40,436 $39,670 $1,796 $1,696 O&R Electric $497 $523 $— $— $37 $38 $86 $85 $1 $(2) $19 $18 $27 $26 $1,985 $1,959 $70 $72 Gas 133 117 — — 13 13 28 — — (2) 9 9 8 (4) 799 754 36 29 Total O&R $630 $640 $— $— $50 $51 $114 $85 $1 $(4) $28 $27 $35 $22 $2,784 $2,713 $106 $101 Competitive energy businesses $998 $1,087 $7 $(5) $30 $16 $184 $53 $36 $33 $23 $5 $76 $24 $2,394 $1,547 $677 $676 Con Edison Transmission — — — — — — (1) — 23 — 4 — — — 1,072 2 — — Other (a) (1) (2) (7) 5 — — 1 1 (1) (2) 11 19 6 3 630 1,039 — — Total Con Edison $9,368 $9,847 $— $— $905 $840 $2,097 $2,028 $61 $23 $517 $486 $620 $574 $47,316 $44,971 $2,579 $2,473 (a) Parent company and consolidation adjustments. Other does not represent a business segment.
CECONY
Segment Reporting Information [Line Items]
Financial Information by Business Segment	Financial Information by Business Segment Con Edison’s principal business segments prior to June 2016 were CECONY’s regulated utility activities, O&R’s regulated utility activities and Con Edison’s competitive energy businesses. CECONY’s principal business segments are its regulated electric, gas and steam utility activities. In 2016, Con Edison Transmission began investing, through CET Electric and CET Gas, in electric transmission and gas pipeline and storage assets (see Note P). As a result of these investments, in June 2016 Con Edison changed its business segments to add Con Edison Transmission as a separate reportable segment based on management’s reporting and decision-making, including performance evaluation and resource allocation. For comparison purposes, the previously reported financial information by business segments was reclassified to reflect the current business segment presentation. The financial data for the business segments are as follows: As of and for the Three Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $2,557 $2,558 $5 $4 $217 $207 $841 $811 $2 $(2) $117 $111 $275 $260 $30,580 $30,369 $411 $419 Gas 208 213 1 1 41 35 (28) (17) — (1) 27 24 (24) (17) 7,300 6,687 224 178 Steam 63 58 22 22 20 20 (47) (49) — — 10 10 (17) (18) 2,556 2,614 24 27 Consolidation adjustments — — (28) (27) — — — — — — — — — — — — — — Total CECONY $2,828 $2,829 $— $— $278 $262 $766 $745 $2 $(3) $154 $145 $234 $225 $40,436 $39,670 $659 $624 O&R Electric $213 $205 $— $— $12 $13 $55 $51 $1 $(4) $6 $6 $20 $17 $1,985 $1,959 $24 $26 Gas 27 24 — — 5 4 (7) (9) — (1) 3 3 (4) (5) 799 754 14 12 Total O&R $240 $229 $— $— $17 $17 $48 $42 $1 $(5) $9 $9 $16 $12 $2,784 $2,713 $38 $38 Competitive energy businesses $350 $386 $(2) $(2) $11 $6 $125 $43 $27 $17 $7 $2 $67 $21 $2,394 $1,547 $121 $212 Con Edison Transmission — — — — — — (1) — 20 — 3 — — — 1,072 2 — — Other (a) (1) (1) 2 2 (1) — 2 — (1) — 5 6 4 2 630 1,039 — — Total Con Edison $3,417 $3,443 $— $— $305 $285 $940 $830 $49 $9 $178 $162 $321 $260 $47,316 $44,971 $818 $874 (a) Parent company and consolidation adjustments. Other does not represent a business segment. As of and for the Nine Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $6,222 $6,416 $13 $13 $645 $610 $1,487 $1,511 $3 $(3) $342 $333 $412 $401 $30,580 $30,369 $1,133 $1,165 Gas 1,113 1,177 4 4 118 105 273 278 (1) (1) 79 71 73 82 7,300 6,687 589 466 Steam 406 529 65 65 62 58 39 100 — — 30 31 18 42 2,556 2,614 74 65 Consolidation adjustments — — (82) (82) — — — — — — — — — — — — — — Total CECONY $7,741 $8,122 $— $— $825 $773 $1,799 $1,889 $2 $(4) $451 $435 $503 $525 $40,436 $39,670 $1,796 $1,696 O&R Electric $497 $523 $— $— $37 $38 $86 $85 $1 $(2) $19 $18 $27 $26 $1,985 $1,959 $70 $72 Gas 133 117 — — 13 13 28 — — (2) 9 9 8 (4) 799 754 36 29 Total O&R $630 $640 $— $— $50 $51 $114 $85 $1 $(4) $28 $27 $35 $22 $2,784 $2,713 $106 $101 Competitive energy businesses $998 $1,087 $7 $(5) $30 $16 $184 $53 $36 $33 $23 $5 $76 $24 $2,394 $1,547 $677 $676 Con Edison Transmission — — — — — — (1) — 23 — 4 — — — 1,072 2 — — Other (a) (1) (2) (7) 5 — — 1 1 (1) (2) 11 19 6 3 630 1,039 — — Total Con Edison $9,368 $9,847 $— $— $905 $840 $2,097 $2,028 $61 $23 $517 $486 $620 $574 $47,316 $44,971 $2,579 $2,473 (a) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2016
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities 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 L), 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 September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 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 $75 $(60) $15 (b) $59 $(41) $18 (b) Current - assets held for sale (c) — — — 51 (50) 1 Noncurrent 58 (57) 1 57 (54) 3 Noncurrent - assets held for sale (c) — — — 15 (15) — Total fair value of derivative assets $133 $(117) $16 $182 $(160) $22 Fair value of derivative liabilities Current $(143) $73 $(70) $(144) $78 $(66) Current - liabilities held for sale (c) — — — (115) 50 (65) Noncurrent (111) 59 (52) (102) 63 (39) Noncurrent - liabilities held for sale (c) — — — (28) 15 (13) Total fair value of derivative liabilities $(254) $132 $(122) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(121) $15 $(106) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $52 $(46) $6 (b) $40 $(32) $8 (b) Noncurrent 45 (45) — 48 (47) 1 Total fair value of derivative assets $97 $(91) $6 $88 $(79) $9 Fair value of derivative liabilities Current $(122) $61 $(61) $(121) $71 $(50) Noncurrent (92) 47 (45) (92) 56 (36) Total fair value of derivative liabilities $(214) $108 $(106) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(117) $17 $(100) (b) $(125) $48 $(77) (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 September 30, 2016 and December 31, 2015 , margin deposits for Con Edison ( $12 million and $26 million , respectively) and CECONY ( $12 million and $26 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) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet. 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. 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. Con Edison’s competitive 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 three and nine months ended September 30, 2016 and 2015 : For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(1) $(1) $(3) $(1) Noncurrent Deferred derivative gains (2) — — — Total deferred gains/(losses) $(3) $(1) $(3) $(1) Current Deferred derivative losses $(19) $8 $(18) $8 Current Recoverable energy costs (39) (53) (35) (49) Noncurrent Deferred derivative losses (17) 14 (14) 13 Total deferred gains/(losses) $(75) $(31) $(67) $(28) Net deferred gains/(losses) $(78) $(32) $(70) $(29) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(37) (a) $(31) (b) $— $— Gas purchased for resale (38) (26) — — Non-utility revenue (2) (a) 5 (b) — — Total pre-tax gain/(loss) recognized in income $(77) $(52) $— $— (a) For the three months ended September 30, 2016 , Con Edison recorded unrealized losses in non-utility operating revenue ( $2 million ) and purchase power expense ( $23 million ). (b) For the three months ended September 30, 2015 , Con Edison recorded in purchased power expense an unrealized pre-tax gain of $12 million . For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $6 $— $2 $1 Noncurrent Deferred derivative gains (1) — (1) — Total deferred gains/(losses) $5 $— $1 $1 Current Deferred derivative losses $19 $40 $16 $40 Current Recoverable energy costs (163) (92) (148) (87) Noncurrent Deferred derivative losses (5) (7) (3) (5) Total deferred gains/(losses) $(149) $(59) $(135) $(52) Net deferred gains/(losses) $(144) $(59) $(134) $(51) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(106) (a) $(60) (b) $— $— Gas purchased for resale (72) (94) — — Non-utility revenue 15 (a) 20 (b) — — Total pre-tax gain/(loss) recognized in income $(163) $(134) $— $— (a) For the nine months ended September 30, 2016 , Con Edison recorded unrealized gains and losses in non-utility operating revenue ( $3 million loss) and purchase power expense ( $11 million gain). (b) For the nine months ended September 30, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $3 million loss) and purchased power expense ( $6 million gain). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at September 30, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 22,797,395 15,472 69,954,738 1,344,000 CECONY 20,724,225 9,000 70,100,000 1,344,000 (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 competitive 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 September 30, 2016 , Con Edison and CECONY had $141 million and $13 million of credit exposure in connection with energy supply and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $77 million with independent system operators, $34 million with investment-grade counterparties, $20 million with commodity exchange brokers, and $10 million with non-investment grade/non-rated counterparties. CECONY’s net credit exposure consisted of $12 million with commodity exchange brokers and $1 million with investment-grade counterparties. 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 September 30, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $111 $97 Collateral posted 24 23 Additional collateral (b) (downgrade one level from current ratings) 18 15 Additional collateral (b) (downgrade to below investment grade from current ratings) 106 (c) 84 (c) (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 competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $10 million at September 30, 2016 . 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 September 30, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $9 million .
CECONY
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities 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 L), 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 September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 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 $75 $(60) $15 (b) $59 $(41) $18 (b) Current - assets held for sale (c) — — — 51 (50) 1 Noncurrent 58 (57) 1 57 (54) 3 Noncurrent - assets held for sale (c) — — — 15 (15) — Total fair value of derivative assets $133 $(117) $16 $182 $(160) $22 Fair value of derivative liabilities Current $(143) $73 $(70) $(144) $78 $(66) Current - liabilities held for sale (c) — — — (115) 50 (65) Noncurrent (111) 59 (52) (102) 63 (39) Noncurrent - liabilities held for sale (c) — — — (28) 15 (13) Total fair value of derivative liabilities $(254) $132 $(122) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(121) $15 $(106) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $52 $(46) $6 (b) $40 $(32) $8 (b) Noncurrent 45 (45) — 48 (47) 1 Total fair value of derivative assets $97 $(91) $6 $88 $(79) $9 Fair value of derivative liabilities Current $(122) $61 $(61) $(121) $71 $(50) Noncurrent (92) 47 (45) (92) 56 (36) Total fair value of derivative liabilities $(214) $108 $(106) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(117) $17 $(100) (b) $(125) $48 $(77) (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 September 30, 2016 and December 31, 2015 , margin deposits for Con Edison ( $12 million and $26 million , respectively) and CECONY ( $12 million and $26 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) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet. 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. 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. Con Edison’s competitive 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 three and nine months ended September 30, 2016 and 2015 : For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(1) $(1) $(3) $(1) Noncurrent Deferred derivative gains (2) — — — Total deferred gains/(losses) $(3) $(1) $(3) $(1) Current Deferred derivative losses $(19) $8 $(18) $8 Current Recoverable energy costs (39) (53) (35) (49) Noncurrent Deferred derivative losses (17) 14 (14) 13 Total deferred gains/(losses) $(75) $(31) $(67) $(28) Net deferred gains/(losses) $(78) $(32) $(70) $(29) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(37) (a) $(31) (b) $— $— Gas purchased for resale (38) (26) — — Non-utility revenue (2) (a) 5 (b) — — Total pre-tax gain/(loss) recognized in income $(77) $(52) $— $— (a) For the three months ended September 30, 2016 , Con Edison recorded unrealized losses in non-utility operating revenue ( $2 million ) and purchase power expense ( $23 million ). (b) For the three months ended September 30, 2015 , Con Edison recorded in purchased power expense an unrealized pre-tax gain of $12 million . For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $6 $— $2 $1 Noncurrent Deferred derivative gains (1) — (1) — Total deferred gains/(losses) $5 $— $1 $1 Current Deferred derivative losses $19 $40 $16 $40 Current Recoverable energy costs (163) (92) (148) (87) Noncurrent Deferred derivative losses (5) (7) (3) (5) Total deferred gains/(losses) $(149) $(59) $(135) $(52) Net deferred gains/(losses) $(144) $(59) $(134) $(51) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(106) (a) $(60) (b) $— $— Gas purchased for resale (72) (94) — — Non-utility revenue 15 (a) 20 (b) — — Total pre-tax gain/(loss) recognized in income $(163) $(134) $— $— (a) For the nine months ended September 30, 2016 , Con Edison recorded unrealized gains and losses in non-utility operating revenue ( $3 million loss) and purchase power expense ( $11 million gain). (b) For the nine months ended September 30, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $3 million loss) and purchased power expense ( $6 million gain). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at September 30, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 22,797,395 15,472 69,954,738 1,344,000 CECONY 20,724,225 9,000 70,100,000 1,344,000 (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 competitive 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 September 30, 2016 , Con Edison and CECONY had $141 million and $13 million of credit exposure in connection with energy supply and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $77 million with independent system operators, $34 million with investment-grade counterparties, $20 million with commodity exchange brokers, and $10 million with non-investment grade/non-rated counterparties. CECONY’s net credit exposure consisted of $12 million with commodity exchange brokers and $1 million with investment-grade counterparties. 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 September 30, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $111 $97 Collateral posted 24 23 Additional collateral (b) (downgrade one level from current ratings) 18 15 Additional collateral (b) (downgrade to below investment grade from current ratings) 106 (c) 84 (c) (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 competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $10 million at September 30, 2016 . 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 September 30, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $9 million .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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 as of September 30, 2016 and December 31, 2015 are summarized below. 2016 2015 (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 $21 $6 $(5) $28 $2 $25 $13 $7 $47 Commodity held for sale (f) — — — — — — 63 1 (63) 1 Other (a)(b)(d) 224 113 — — 337 185 112 — — 297 Total assets $230 $134 $6 $(5) $365 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $3 $146 $5 $(32) $122 $16 $153 $1 $(65) $105 Commodity held for sale (f) — — — — — 1 133 7 (63) 78 Total liabilities $3 $146 $5 $(32) $122 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $4 $7 $1 $6 $18 $1 $9 $8 $17 $35 Other (a)(b)(d) 200 108 — — 308 171 105 — — 276 Total assets $204 $115 $1 $6 $326 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $2 $126 $1 $(23) $106 $14 $129 $— $(57) $86 (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. There were no transfers between levels 1, 2 and 3 for the nine months ended September 30, 2016 and for the year ended December 31, 2015 . (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 September 30, 2016 and December 31, 2015 , 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) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet. 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 competitive energy businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at September 30, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $19.75-$80.00 per MWh 1 Discounted Cash Flow Forward capacity prices (a) $2.68-$9.45 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(0.14)-$2.82 per MWh Total Con Edison—Commodity $1 CECONY—Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $21.10-$80.00 per MWh Transmission Congestion Contracts $1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Total CECONY—Commodity $— (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 as of September 30, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of July 1, $5 $13 $2 $11 Included in earnings (4) (4) — (1) Included in regulatory assets and liabilities (5) (1) (3) (1) Purchases — 1 — 1 Sales (a) 4 — — — Settlements 1 (5) 1 (2) Ending balance as of September 30, $1 $4 $— $8 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (1) (18) (1) (5) Included in regulatory assets and liabilities (11) (1) (6) (1) Purchases 2 9 1 5 Sales (a) 4 — — — Settlements 1 (6) (2) (4) Ending balance as of September 30, $1 $4 $— $8 (a) Amounts represent derivative instruments novated as part of the assets of Con Edison Solutions’ retail electric supply business which were sold to a subsidiary of Exelon Corporation (see Note P). 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. 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 competitive energy businesses, realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues (immaterial for both periods) and purchased power costs ( $5 million loss and $3 million loss ) on the consolidated income statement for the three months ended September 30, 2016 and 2015 , respectively. Realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues ( immaterial for both periods) and purchased power costs ( $6 million loss and $12 million loss ) on the consolidated income statement for the nine months ended September 30, 2016 , and 2015 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at September 30, 2016 and 2015 is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $4 million loss and $3 million loss ) on the consolidated income statement for the three months ended September 30, 2016 and 2015 , respectively. For the nine months ended September 30, 2016 , and 2015 , the change in fair value relating to Level 3 commodity derivative assets and liabilities is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $2 million loss and $8 million loss ) on the consolidated income statement, respectively.
CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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 as of September 30, 2016 and December 31, 2015 are summarized below. 2016 2015 (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 $21 $6 $(5) $28 $2 $25 $13 $7 $47 Commodity held for sale (f) — — — — — — 63 1 (63) 1 Other (a)(b)(d) 224 113 — — 337 185 112 — — 297 Total assets $230 $134 $6 $(5) $365 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $3 $146 $5 $(32) $122 $16 $153 $1 $(65) $105 Commodity held for sale (f) — — — — — 1 133 7 (63) 78 Total liabilities $3 $146 $5 $(32) $122 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $4 $7 $1 $6 $18 $1 $9 $8 $17 $35 Other (a)(b)(d) 200 108 — — 308 171 105 — — 276 Total assets $204 $115 $1 $6 $326 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $2 $126 $1 $(23) $106 $14 $129 $— $(57) $86 (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. There were no transfers between levels 1, 2 and 3 for the nine months ended September 30, 2016 and for the year ended December 31, 2015 . (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 September 30, 2016 and December 31, 2015 , 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) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet. 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 competitive energy businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at September 30, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $19.75-$80.00 per MWh 1 Discounted Cash Flow Forward capacity prices (a) $2.68-$9.45 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(0.14)-$2.82 per MWh Total Con Edison—Commodity $1 CECONY—Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $21.10-$80.00 per MWh Transmission Congestion Contracts $1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Total CECONY—Commodity $— (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 as of September 30, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of July 1, $5 $13 $2 $11 Included in earnings (4) (4) — (1) Included in regulatory assets and liabilities (5) (1) (3) (1) Purchases — 1 — 1 Sales (a) 4 — — — Settlements 1 (5) 1 (2) Ending balance as of September 30, $1 $4 $— $8 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (1) (18) (1) (5) Included in regulatory assets and liabilities (11) (1) (6) (1) Purchases 2 9 1 5 Sales (a) 4 — — — Settlements 1 (6) (2) (4) Ending balance as of September 30, $1 $4 $— $8 (a) Amounts represent derivative instruments novated as part of the assets of Con Edison Solutions’ retail electric supply business which were sold to a subsidiary of Exelon Corporation (see Note P). 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. 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 competitive energy businesses, realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues (immaterial for both periods) and purchased power costs ( $5 million loss and $3 million loss ) on the consolidated income statement for the three months ended September 30, 2016 and 2015 , respectively. Realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues ( immaterial for both periods) and purchased power costs ( $6 million loss and $12 million loss ) on the consolidated income statement for the nine months ended September 30, 2016 , and 2015 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at September 30, 2016 and 2015 is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $4 million loss and $3 million loss ) on the consolidated income statement for the three months ended September 30, 2016 and 2015 , respectively. For the nine months ended September 30, 2016 , and 2015 , the change in fair value relating to Level 3 commodity derivative assets and liabilities is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $2 million loss and $8 million loss ) on the consolidated income statement, respectively.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Variable Interest Entities	Variable Interest Entities Con Edison enters into arrangements including leases, partnerships and electricity purchase agreements, with various entities. As a result of these arrangements, Con Edison retains or may retain a variable interest in these entities. CECONY had a variable interest in a non-consolidated variable interest entity (VIE), Astoria Energy, LLC (Astoria Energy), with which CECONY entered into a long-term electricity purchase agreement that expired in April 2016. CECONY has ongoing long-term electricity purchase agreements with the following two potential VIEs: Cogen Technologies Linden Venture, LP, and Brooklyn Navy Yard Cogeneration Partners, LP. In 2015 , requests were made of these two counterparties 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. The payments for these contracts constitute CECONY’s maximum exposure to loss with respect to the potential VIEs. The following table summarizes the VIEs in which Con Edison Development has entered into as of September 30, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $179 Panoche Valley (d) 120 20 2015 California 274 Mesquite Solar 1 83 20 2013 Arizona 107 Copper Mountain Solar 2 75 25 2013 Nevada 84 California Solar 55 25 2012 California 70 Broken Bow II 38 25 2014 Nebraska 51 Texas Solar 4 32 25 2014 Texas 43 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. 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 Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) In October 2016, Con Edison Development acquired the remaining 50 percent ownership interest in the project. See Note P.
CECONY
Schedule of Equity Method Investments [Line Items]
Variable Interest Entities	Variable Interest Entities Con Edison enters into arrangements including leases, partnerships and electricity purchase agreements, with various entities. As a result of these arrangements, Con Edison retains or may retain a variable interest in these entities. CECONY had a variable interest in a non-consolidated variable interest entity (VIE), Astoria Energy, LLC (Astoria Energy), with which CECONY entered into a long-term electricity purchase agreement that expired in April 2016. CECONY has ongoing long-term electricity purchase agreements with the following two potential VIEs: Cogen Technologies Linden Venture, LP, and Brooklyn Navy Yard Cogeneration Partners, LP. In 2015 , requests were made of these two counterparties 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. The payments for these contracts constitute CECONY’s maximum exposure to loss with respect to the potential VIEs. The following table summarizes the VIEs in which Con Edison Development has entered into as of September 30, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $179 Panoche Valley (d) 120 20 2015 California 274 Mesquite Solar 1 83 20 2013 Arizona 107 Copper Mountain Solar 2 75 25 2013 Nevada 84 California Solar 55 25 2012 California 70 Broken Bow II 38 25 2014 Nebraska 51 Texas Solar 4 32 25 2014 Texas 43 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. 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 Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) In October 2016, Con Edison Development acquired the remaining 50 percent ownership interest in the project. See Note P.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2016
Related Party Transactions	Related Party 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 (see Note P). The Utilities bill NY Transco for such work and expenses in accordance with established policies. For the three and nine months ended September 30, 2016, the amounts billed by CECONY to NY Transco were immaterial. 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) (see Note P). In addition, CECONY is the replacement shipper on one of Crestwood’s firm transportation agreements with Tennessee Gas Pipeline Company LLC. For the three months ended September 30, 2016, the amount of storage and wheeling services received by CECONY from Stagecoach was $8 million . Since the formation of the joint venture in June 2016, the amount of storage and wheeling services received by CECONY from Stagecoach was $10 million . CECONY has a financial electric capacity contract with Con Edison Energy for the period May 2016 through April 2017. For the three and nine months ended September 30, 2016, Con Edison Energy's realized losses under this contract were $1 million . At September 30, 2016 Con Edison Development has an outstanding note receivable of $234 million from Panoche Valley, a solar electric production project in which Con Edison Development has an ownership interest of 50 percent (see Note M). In October 2016, Con Edison Development acquired the remaining 50 percent interest in the project (see Note P).
CECONY
Related Party Transactions	Related Party 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 (see Note P). The Utilities bill NY Transco for such work and expenses in accordance with established policies. For the three and nine months ended September 30, 2016, the amounts billed by CECONY to NY Transco were immaterial. 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) (see Note P). In addition, CECONY is the replacement shipper on one of Crestwood’s firm transportation agreements with Tennessee Gas Pipeline Company LLC. For the three months ended September 30, 2016, the amount of storage and wheeling services received by CECONY from Stagecoach was $8 million . Since the formation of the joint venture in June 2016, the amount of storage and wheeling services received by CECONY from Stagecoach was $10 million . CECONY has a financial electric capacity contract with Con Edison Energy for the period May 2016 through April 2017. For the three and nine months ended September 30, 2016, Con Edison Energy's realized losses under this contract were $1 million . At September 30, 2016 Con Edison Development has an outstanding note receivable of $234 million from Panoche Valley, a solar electric production project in which Con Edison Development has an ownership interest of 50 percent (see Note M). In October 2016, Con Edison Development acquired the remaining 50 percent interest in the project (see Note P).

New Financial Accounting Standa

New Financial Accounting Standards	9 Months Ended
	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10,“Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. Furthermore in May 2016, the FASB issued ASU No. 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients” to clarify assessing collectibility, presentation of sales taxes, noncash consideration, contract modification at transition, and completed contracts at transition. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. 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). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. 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 May 2016, the FASB issued amendments to the guidance on revenue recognition and derivatives and hedging through ASU 2016-11, “Revenue Recognition (Topic 605) and Derivatives and Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting (SEC Update).” The amendment rescinds certain SEC guidance superseded by the newly issued revenue recognition and hedging guidance (ASU 2014-09 and 2014-16 respectively). The amendments will be effective upon adoption of the 2014-09 and 2014-16. The Companies are in the process of evaluating the potential impact of the amendments on the Companies’ financial position, results of operations and liquidity. In June 2016, the FASB issued amendments to the guidance for recognition of credit losses for financial instruments through ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendment replaces the incurred loss impairment methodology which involved delayed recognition of credit losses. As the updated guidance now requires credit losses to be recognized when expected rather than when incurred, a broader range of reasonable and supportable information must be considered in developing the credit loss estimates. This includes financial instruments that are valued at amortized cost and available for sale. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted for reporting periods beginning after December 15, 2018. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In August 2016, the FASB issued amendments to the guidance for the Statement of Cash Flows through ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force).” The amendment specifies the classification and presentation of certain cash flow items to reduce diversity in practice. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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 October 2016, the FASB issued amendments to the guidance for Income Taxes through ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” The amendment clarifies the tax treatment of intra-entity transfers of assets other than inventory. The updated guidance requires entities recognize the income tax consequences of an intra-entity transfer of assets other than inventory when the transfer occurs. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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.
CECONY
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10,“Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. Furthermore in May 2016, the FASB issued ASU No. 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients” to clarify assessing collectibility, presentation of sales taxes, noncash consideration, contract modification at transition, and completed contracts at transition. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. 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). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. 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 May 2016, the FASB issued amendments to the guidance on revenue recognition and derivatives and hedging through ASU 2016-11, “Revenue Recognition (Topic 605) and Derivatives and Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting (SEC Update).” The amendment rescinds certain SEC guidance superseded by the newly issued revenue recognition and hedging guidance (ASU 2014-09 and 2014-16 respectively). The amendments will be effective upon adoption of the 2014-09 and 2014-16. The Companies are in the process of evaluating the potential impact of the amendments on the Companies’ financial position, results of operations and liquidity. In June 2016, the FASB issued amendments to the guidance for recognition of credit losses for financial instruments through ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendment replaces the incurred loss impairment methodology which involved delayed recognition of credit losses. As the updated guidance now requires credit losses to be recognized when expected rather than when incurred, a broader range of reasonable and supportable information must be considered in developing the credit loss estimates. This includes financial instruments that are valued at amortized cost and available for sale. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted for reporting periods beginning after December 15, 2018. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In August 2016, the FASB issued amendments to the guidance for the Statement of Cash Flows through ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force).” The amendment specifies the classification and presentation of certain cash flow items to reduce diversity in practice. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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 October 2016, the FASB issued amendments to the guidance for Income Taxes through ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” The amendment clarifies the tax treatment of intra-entity transfers of assets other than inventory. The updated guidance requires entities recognize the income tax consequences of an intra-entity transfer of assets other than inventory when the transfer occurs. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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.

Acquisitions, Investments and D

Acquisitions, Investments and Dispositions	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Acquisitions, Investments and Dispositions	Acquisitions, Investments and Dispositions Acquisitions and Investments Texas Solar 7 In January 2016, Con Edison Development acquired a 100 percent interest in a company that is the owner of a 106 MW (AC) solar electric production project in Texas (Texas Solar 7) for $227 million ; $218 million was recorded as non-utility construction work in progress and the remaining $9 million was recorded as other receivables. At September 30, 2016 net assets of the project are approximately $123 million . The project has been financed, in part, by debt secured by the project (see Note C). Electricity generated by this project is to be purchased by the City of San Antonio pursuant to a long-term power purchase agreement. The project commenced commercial operation in the third quarter of 2016. Con Edison's interest in Texas Solar 7 is consolidated in the financial statements. Mountain Valley Pipeline In January 2016, CET Gas acquired a 12.5 percent equity interest in Mountain Valley Pipeline, LLC (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 September 30, 2016 , CET Gas' investment in MVP was $41 million . The estimated total project cost is $3,000 million to $3,500 million . Subject to FERC approval, MVP is targeting to be fully in-service during 2018. Con Edison is accounting for its equity interest in MVP as an equity method investment. Stagecoach Gas Services In April 2016, a CET Gas subsidiary agreed with a subsidiary of Crestwood to form a joint venture to own, operate and further develop existing natural gas pipeline and storage businesses located in northern Pennsylvania and southern New York. The transaction was substantially completed during June 2016. Crestwood contributed businesses to a new entity, Stagecoach, and the CET Gas subsidiary purchased a 50 percent equity interest in Stagecoach for $945 million (subject to closing adjustments). At September 30, 2016 , CET Gas' investment in Stagecoach was $968 million . Con Edison is accounting for its equity interest in Stagecoach as an equity method investment. NY Transco In January 2016, CECONY entered into an agreement to transfer certain electric transmission projects to NY Transco, a company in which CET Electric has a 45.7 percent equity interest. In April 2016, the NYSPSC authorized CECONY, subject to certain conditions, to transfer the projects to NY Transco. In May 2016, CECONY transferred the projects to NY Transco for a purchase price of $122 million and an $8 million payment for easement rights on certain associated property. At September 30, 2016 , CET Electric's investment in NY Transco was $53 million . Con Edison is accounting for its equity interest in NY Transco 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 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 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). The impairment charge and bargain purchase gain are included in Investment and other income on Con Edison’s consolidated income statement. Con Edison's interest in Pilesgrove is consolidated in the financial statements subsequent to the August 2016 acquisition. At September 30, 2016 , net assets of the project are approximately $48 million , consisting primarily of $45 million recorded as non-utility property and $3 million recorded in current assets. Panoche Valley In October 2016, Con Edison Development acquired the remaining 50 percent interest in Panoche Holdings, LLC, which is developing a 240 MW (AC) solar electric production project in California, for cash consideration of $37 million , net of applicable purchase price adjustments. Con Edison will consolidate the project on its financial statements as of the date of acquisition. See Note M. Dispositions Pike County Light & Power Company (Pike) In October 2015, upon evaluating strategic alternatives, O&R entered into an agreement to sell Pike to Corning Natural Gas Holding Corporation (Corning). In August 2016, the sale was completed. O&R received cash consideration of $15 million for the sale. O&R has agreed to provide transition services to Corning for operations and customer support for a period of up to 18 months subsequent to the sale. In addition, O&R will continue to purchase and sell to Pike electric and gas commodity for three years . Pike has an option to extend the service for up to an additional three years . At September 30, 2015, O&R recorded an impairment charge of $5 million ( $3 million , net of taxes), representing the difference between the carrying amount of Pike’s assets and the estimated sales proceeds. At December 31, 2015, Pike’s total assets and liabilities held for sale were $23 million and $5 million , respectively. There were no amounts outstanding at September 30, 2016. 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 ( $47 million , net of taxes), inclusive of a $65 million ( $42 million , net of taxes) gain on derivative instruments. The tax effect of the sale includes $29 million ( $19 million , net of federal tax) of state taxes related to a change in the apportionment of state income taxes. Con Edison Solutions has agreed to provide transition services to the Exelon subsidiary for operations and customer support through the end of 2017 during which period certain guarantees or other credit support provided by Con Edison in connection with the retail electric supply business may continue in effect. See Note H. At December 31, 2015, Con Edison Solutions' total assets and liabilities held for sale were $134 million and $84 million , respectively. There were no amounts outstanding at September 30, 2016.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10,“Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. Furthermore in May 2016, the FASB issued ASU No. 2016-12, “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients” to clarify assessing collectibility, presentation of sales taxes, noncash consideration, contract modification at transition, and completed contracts at transition. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. 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). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. 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 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. 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 May 2016, the FASB issued amendments to the guidance on revenue recognition and derivatives and hedging through ASU 2016-11, “Revenue Recognition (Topic 605) and Derivatives and Hedging (Topic 815): Rescission of SEC Guidance Because of Accounting Standards Updates 2014-09 and 2014-16 Pursuant to Staff Announcements at the March 3, 2016 EITF Meeting (SEC Update).” The amendment rescinds certain SEC guidance superseded by the newly issued revenue recognition and hedging guidance (ASU 2014-09 and 2014-16 respectively). The amendments will be effective upon adoption of the 2014-09 and 2014-16. The Companies are in the process of evaluating the potential impact of the amendments on the Companies’ financial position, results of operations and liquidity. In June 2016, the FASB issued amendments to the guidance for recognition of credit losses for financial instruments through ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendment replaces the incurred loss impairment methodology which involved delayed recognition of credit losses. As the updated guidance now requires credit losses to be recognized when expected rather than when incurred, a broader range of reasonable and supportable information must be considered in developing the credit loss estimates. This includes financial instruments that are valued at amortized cost and available for sale. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted for reporting periods beginning after December 15, 2018. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In August 2016, the FASB issued amendments to the guidance for the Statement of Cash Flows through ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force).” The amendment specifies the classification and presentation of certain cash flow items to reduce diversity in practice. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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 October 2016, the FASB issued amendments to the guidance for Income Taxes through ASU 2016-16, “Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” The amendment clarifies the tax treatment of intra-entity transfers of assets other than inventory. The updated guidance requires entities recognize the income tax consequences of an intra-entity transfer of assets other than inventory when the transfer occurs. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. 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.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Earnings Per Common Share	For the three and nine months ended September 30, 2016 and 2015 , basic and diluted earnings per share (EPS) for Con Edison are calculated as follows: For the Three Months Ended September 30, For the Nine Months Ended September 30, (Millions of Dollars, except per share amounts/Shares in Millions) 2016 2015 2016 2015 Net income $497 $428 $1,039 $1,017 Weighted average common shares outstanding – basic 304.5 292.9 299.1 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.4 1.3 1.4 1.3 Adjusted weighted average common shares outstanding – diluted 305.9 294.2 300.5 294.2 Net income per common share – basic $1.63 $1.46 $3.47 $3.47 Net income per common share – diluted $1.62 $1.45 $3.46 $3.46
Changes in Accumulated Other Comprehensive Income/(Loss) by Component	For the three and nine months ended September 30, 2016 and 2015 , changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(33) $(39) $(8) $(10) Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 1 — 1 Current period OCI, net of taxes 1 1 — 1 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(2) and $(3) for Con Edison in 2016 and 2015 (a)(b) 3 4 1 2 Current period OCI, net of taxes 2 7 1 2 Ending balance, accumulated OCI, net of taxes $(32) $(38) $(8) $(9) (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 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.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
	Sep. 30, 2016
Regulated Operations [Abstract]
Summary of Rate Plan	The following table contains a summary of the electric rate plan. Effective period January 2017 - December 2019 Base rate changes (a) Yr. 1 - $195 million Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $84 million Other revenue sources Retention of $75 million of annual transmission congestion revenues. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized electric delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased power and fuel costs. Negative revenue adjustments Potential penalties if certain performance targets relating to service, reliability, safety and other matters are not met: Yr. 1 - $376 million; Yr. 2 - $383 million; and Yr. 3 - $395 million. Cost reconciliations Continuation of reconciliation of expenses for pension and other postretirement benefits, variable-rate tax-exempt debt, major storms, property taxes(b), municipal infrastructure support costs(c), 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: Average rate base Yr. 1 - $18,902 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The electric base rate increases shown above are in addition to a $48 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. At the NYSPSC’s option, these increases may be implemented with increases of $199 million in each rate year. (b) 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. (c) 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. (d) 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. The following table contains a summary of the gas rate plan. Effective period January 2017 - December 2019 Base rate changes Yr. 1 - $(5) million(a) Amortizations to income of net regulatory (assets) liabilities Yr. 1 - $39 million Other revenue sources Retention of annual revenues from non-firm customers of up to $65 million and 15 percent of any such revenues above $65 million. Revenue decoupling mechanism Continuation of reconciliation of actual to authorized gas delivery revenues. Recoverable energy costs Continuation of current rate recovery of purchased gas costs. Negative revenue adjustments Potential penalties if performance targets relating to service, safety and other matters are not met: Yr. 1 - $68 million; Yr. 2 - $75 million; and Yr. 3 - $83 million. Cost reconciliations 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.(b) Net utility plant reconciliations Target levels reflected in rates: Average rate base Yr. 1 - $4,841 million Weighted average cost of capital (after-tax) Yr. 1 - 6.82 percent Authorized return on common equity 9.00 percent Earnings sharing 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 - 4.93 percent Common equity ratio 48 percent (a) The base rate decrease is offset by a $41 million increase resulting from the December 2016 expiration of a temporary credit under the current rate plan. (b) See footnotes (b), (c) and (d) to the table under “CECONY-Electric,” above.
Regulatory Assets and Liabilities	Regulatory assets and liabilities at September 30, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,369 $3,876 $3,220 $3,697 Future income tax 2,429 2,350 2,312 2,232 Environmental remediation costs 823 904 720 800 Revenue taxes 298 253 283 240 Deferred storm costs 89 185 30 110 Deferred derivative losses 55 50 49 46 Unamortized loss on reacquired debt 45 50 43 48 Surcharge for New York State assessment 43 44 40 40 O&R property tax reconciliation 39 46 — — Pension and other postretirement benefits deferrals 34 45 3 16 Net electric deferrals 29 44 29 44 Preferred stock redemption 25 26 25 26 O&R transition bond charges 16 21 — — Workers’ compensation 15 11 15 11 Recoverable energy costs 7 16 5 15 Other 228 175 212 157 Regulatory assets – noncurrent 7,544 8,096 6,986 7,482 Deferred derivative losses 94 113 87 103 Recoverable energy costs 25 19 24 18 Regulatory assets – current 119 132 111 121 Total Regulatory Assets $7,663 $8,228 $7,097 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $713 $676 $602 $570 Property tax reconciliation 205 303 205 303 Pension and other postretirement benefit deferrals 163 76 130 46 Net unbilled revenue deferrals 121 109 121 109 Prudence proceeding 96 99 96 99 Unrecognized other postretirement costs 91 28 91 28 New York State income tax rate change 66 75 64 72 Base rate change deferrals 62 128 62 128 Variable-rate tax-exempt debt – cost rate reconciliation 60 70 52 60 Carrying charges on repair allowance and bonus depreciation 57 49 56 48 Earnings sharing - electric, gas and steam 34 80 26 80 Net utility plant reconciliations 27 32 27 31 Property tax refunds 12 44 12 44 World Trade Center settlement proceeds 5 21 5 21 Other 208 187 176 150 Regulatory liabilities – noncurrent 1,920 1,977 1,725 1,789 Revenue decoupling mechanism 74 45 70 45 Refundable energy costs 37 64 18 33 Deferred derivative gains 12 6 8 6 Regulatory liabilities – current 123 115 96 84 Total Regulatory Liabilities $2,043 $2,092 $1,821 $1,873

Capitalization (Tables)

Capitalization (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Carrying Amounts and Fair Values of Long-Term Debt	The carrying amounts and fair values of long-term debt at September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $14,093 $16,325 $12,745 $13,856 CECONY $11,584 $13,564 $11,437 $12,427

Pension Benefits (Tables)

Pension Benefits (Tables)	9 Months Ended
	Sep. 30, 2016
Pension Benefits
Total Periodic Benefit Costs	The components of the Companies’ total periodic benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — NET PERIODIC BENEFIT COST $131 $191 $121 $178 Amortization of regulatory asset — 1 — 1 TOTAL PERIODIC BENEFIT COST $131 $192 $121 $179 Cost capitalized (51) (80) (49) (76) Reconciliation to rate level 10 (14) 13 (14) Cost charged to operating expenses $90 $98 $85 $89 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $207 $223 $194 $209 Interest cost on projected benefit obligation 447 431 419 404 Expected return on plan assets (711) (664) (674) (630) Recognition of net actuarial loss 447 581 424 550 Recognition of prior service costs 3 3 1 1 NET PERIODIC BENEFIT COST $393 $574 $364 $534 Amortization of regulatory asset — 2 — 2 TOTAL PERIODIC BENEFIT COST $393 $576 $364 $536 Cost capitalized (157) (224) (148) (214) Reconciliation to rate level 35 (56) 39 (56) Cost charged to operating expenses $271 $296 $255 $266

Other Postretirement Benefits (

Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2016
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Periodic Benefit Costs	The components of the Companies’ total periodic other postretirement benefit costs for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (3) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(6) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 6 2 Cost charged to operating expenses $2 $4 $2 $2 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $13 $15 $10 $11 Interest cost on accumulated other postretirement benefit obligation 36 38 30 32 Expected return on plan assets (58) (59) (50) (51) Recognition of net actuarial loss 4 24 2 21 Recognition of prior service cost (15) (15) (11) (10) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(20) $3 $(19) $3 Cost capitalized 5 (2) 5 (2) Reconciliation to rate level 20 12 19 5 Cost charged to operating expenses $5 $13 $5 $6

Environmental Matters (Tables)

Environmental Matters (Tables)	9 Months Ended
	Sep. 30, 2016
Environmental Remediation Obligations [Abstract]
Accrued Liabilities and Regulatory Assets	The accrued liabilities and regulatory assets related to Superfund Sites at September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $664 $679 $574 $579 Other Superfund Sites 88 86 87 86 Total $752 $765 $661 $665 Regulatory assets $823 $904 $720 $800
Environmental Remediation Costs	Environmental remediation costs incurred related to Superfund Sites for the three and nine months ended September 30, 2016 and 2015 were as follows: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $8 $6 $5 $6 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $20 $21 $10 $18
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 September 30, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $90 $86 $85 $81 Regulatory assets – workers’ compensation $15 $11 $15 $11

Other Material Contingencies (T

Other Material Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Total Guarantees	A summary, by type and term, of Con Edison’s total guarantees at September 30, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $618 $430 $— $1,048 Energy transactions 635 57 91 783 Renewable electric production projects 445 — 18 463 Other 128 — — 128 Total $1,826 $487 $109 $2,422

Financial Information by Busi33

Financial Information by Business Segment (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Financial Data for Business Segments	The financial data for the business segments are as follows: As of and for the Three Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $2,557 $2,558 $5 $4 $217 $207 $841 $811 $2 $(2) $117 $111 $275 $260 $30,580 $30,369 $411 $419 Gas 208 213 1 1 41 35 (28) (17) — (1) 27 24 (24) (17) 7,300 6,687 224 178 Steam 63 58 22 22 20 20 (47) (49) — — 10 10 (17) (18) 2,556 2,614 24 27 Consolidation adjustments — — (28) (27) — — — — — — — — — — — — — — Total CECONY $2,828 $2,829 $— $— $278 $262 $766 $745 $2 $(3) $154 $145 $234 $225 $40,436 $39,670 $659 $624 O&R Electric $213 $205 $— $— $12 $13 $55 $51 $1 $(4) $6 $6 $20 $17 $1,985 $1,959 $24 $26 Gas 27 24 — — 5 4 (7) (9) — (1) 3 3 (4) (5) 799 754 14 12 Total O&R $240 $229 $— $— $17 $17 $48 $42 $1 $(5) $9 $9 $16 $12 $2,784 $2,713 $38 $38 Competitive energy businesses $350 $386 $(2) $(2) $11 $6 $125 $43 $27 $17 $7 $2 $67 $21 $2,394 $1,547 $121 $212 Con Edison Transmission — — — — — — (1) — 20 — 3 — — — 1,072 2 — — Other (a) (1) (1) 2 2 (1) — 2 — (1) — 5 6 4 2 630 1,039 — — Total Con Edison $3,417 $3,443 $— $— $305 $285 $940 $830 $49 $9 $178 $162 $321 $260 $47,316 $44,971 $818 $874 (a) Parent company and consolidation adjustments. Other does not represent a business segment. As of and for the Nine Months Ended September 30, Operating revenues Inter-segment revenues Depreciation and amortization Operating income Other income (deductions) Interest charges Income taxes on operating income Total assets Construction expenditures (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $6,222 $6,416 $13 $13 $645 $610 $1,487 $1,511 $3 $(3) $342 $333 $412 $401 $30,580 $30,369 $1,133 $1,165 Gas 1,113 1,177 4 4 118 105 273 278 (1) (1) 79 71 73 82 7,300 6,687 589 466 Steam 406 529 65 65 62 58 39 100 — — 30 31 18 42 2,556 2,614 74 65 Consolidation adjustments — — (82) (82) — — — — — — — — — — — — — — Total CECONY $7,741 $8,122 $— $— $825 $773 $1,799 $1,889 $2 $(4) $451 $435 $503 $525 $40,436 $39,670 $1,796 $1,696 O&R Electric $497 $523 $— $— $37 $38 $86 $85 $1 $(2) $19 $18 $27 $26 $1,985 $1,959 $70 $72 Gas 133 117 — — 13 13 28 — — (2) 9 9 8 (4) 799 754 36 29 Total O&R $630 $640 $— $— $50 $51 $114 $85 $1 $(4) $28 $27 $35 $22 $2,784 $2,713 $106 $101 Competitive energy businesses $998 $1,087 $7 $(5) $30 $16 $184 $53 $36 $33 $23 $5 $76 $24 $2,394 $1,547 $677 $676 Con Edison Transmission — — — — — — (1) — 23 — 4 — — — 1,072 2 — — Other (a) (1) (2) (7) 5 — — 1 1 (1) (2) 11 19 6 3 630 1,039 — — Total Con Edison $9,368 $9,847 $— $— $905 $840 $2,097 $2,028 $61 $23 $517 $486 $620 $574 $47,316 $44,971 $2,579 $2,473 (a) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and He34

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values of Commodity Derivatives Including Offsetting Assets	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 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 $75 $(60) $15 (b) $59 $(41) $18 (b) Current - assets held for sale (c) — — — 51 (50) 1 Noncurrent 58 (57) 1 57 (54) 3 Noncurrent - assets held for sale (c) — — — 15 (15) — Total fair value of derivative assets $133 $(117) $16 $182 $(160) $22 Fair value of derivative liabilities Current $(143) $73 $(70) $(144) $78 $(66) Current - liabilities held for sale (c) — — — (115) 50 (65) Noncurrent (111) 59 (52) (102) 63 (39) Noncurrent - liabilities held for sale (c) — — — (28) 15 (13) Total fair value of derivative liabilities $(254) $132 $(122) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(121) $15 $(106) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $52 $(46) $6 (b) $40 $(32) $8 (b) Noncurrent 45 (45) — 48 (47) 1 Total fair value of derivative assets $97 $(91) $6 $88 $(79) $9 Fair value of derivative liabilities Current $(122) $61 $(61) $(121) $71 $(50) Noncurrent (92) 47 (45) (92) 56 (36) Total fair value of derivative liabilities $(214) $108 $(106) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(117) $17 $(100) (b) $(125) $48 $(77) (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 September 30, 2016 and December 31, 2015 , margin deposits for Con Edison ( $12 million and $26 million , respectively) and CECONY ( $12 million and $26 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) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet.
Fair Values of Commodity Derivatives Including Offsetting Liabilities	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at September 30, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 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 $75 $(60) $15 (b) $59 $(41) $18 (b) Current - assets held for sale (c) — — — 51 (50) 1 Noncurrent 58 (57) 1 57 (54) 3 Noncurrent - assets held for sale (c) — — — 15 (15) — Total fair value of derivative assets $133 $(117) $16 $182 $(160) $22 Fair value of derivative liabilities Current $(143) $73 $(70) $(144) $78 $(66) Current - liabilities held for sale (c) — — — (115) 50 (65) Noncurrent (111) 59 (52) (102) 63 (39) Noncurrent - liabilities held for sale (c) — — — (28) 15 (13) Total fair value of derivative liabilities $(254) $132 $(122) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(121) $15 $(106) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $52 $(46) $6 (b) $40 $(32) $8 (b) Noncurrent 45 (45) — 48 (47) 1 Total fair value of derivative assets $97 $(91) $6 $88 $(79) $9 Fair value of derivative liabilities Current $(122) $61 $(61) $(121) $71 $(50) Noncurrent (92) 47 (45) (92) 56 (36) Total fair value of derivative liabilities $(214) $108 $(106) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(117) $17 $(100) (b) $(125) $48 $(77) (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 September 30, 2016 and December 31, 2015 , margin deposits for Con Edison ( $12 million and $26 million , respectively) and CECONY ( $12 million and $26 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) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet.
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 three and nine months ended September 30, 2016 and 2015 : For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(1) $(1) $(3) $(1) Noncurrent Deferred derivative gains (2) — — — Total deferred gains/(losses) $(3) $(1) $(3) $(1) Current Deferred derivative losses $(19) $8 $(18) $8 Current Recoverable energy costs (39) (53) (35) (49) Noncurrent Deferred derivative losses (17) 14 (14) 13 Total deferred gains/(losses) $(75) $(31) $(67) $(28) Net deferred gains/(losses) $(78) $(32) $(70) $(29) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(37) (a) $(31) (b) $— $— Gas purchased for resale (38) (26) — — Non-utility revenue (2) (a) 5 (b) — — Total pre-tax gain/(loss) recognized in income $(77) $(52) $— $— (a) For the three months ended September 30, 2016 , Con Edison recorded unrealized losses in non-utility operating revenue ( $2 million ) and purchase power expense ( $23 million ). (b) For the three months ended September 30, 2015 , Con Edison recorded in purchased power expense an unrealized pre-tax gain of $12 million . For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $6 $— $2 $1 Noncurrent Deferred derivative gains (1) — (1) — Total deferred gains/(losses) $5 $— $1 $1 Current Deferred derivative losses $19 $40 $16 $40 Current Recoverable energy costs (163) (92) (148) (87) Noncurrent Deferred derivative losses (5) (7) (3) (5) Total deferred gains/(losses) $(149) $(59) $(135) $(52) Net deferred gains/(losses) $(144) $(59) $(134) $(51) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(106) (a) $(60) (b) $— $— Gas purchased for resale (72) (94) — — Non-utility revenue 15 (a) 20 (b) — — Total pre-tax gain/(loss) recognized in income $(163) $(134) $— $— (a) For the nine months ended September 30, 2016 , Con Edison recorded unrealized gains and losses in non-utility operating revenue ( $3 million loss) and purchase power expense ( $11 million gain). (b) For the nine months ended September 30, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $3 million loss) and purchased power expense ( $6 million gain).
Hedged Volume of Derivative Transactions	The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at September 30, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 22,797,395 15,472 69,954,738 1,344,000 CECONY 20,724,225 9,000 70,100,000 1,344,000 (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 September 30, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $111 $97 Collateral posted 24 23 Additional collateral (b) (downgrade one level from current ratings) 18 15 Additional collateral (b) (downgrade to below investment grade from current ratings) 106 (c) 84 (c) (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 competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $10 million at September 30, 2016 . 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 September 30, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $9 million .

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
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 as of September 30, 2016 and December 31, 2015 are summarized below. 2016 2015 (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 $21 $6 $(5) $28 $2 $25 $13 $7 $47 Commodity held for sale (f) — — — — — — 63 1 (63) 1 Other (a)(b)(d) 224 113 — — 337 185 112 — — 297 Total assets $230 $134 $6 $(5) $365 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $3 $146 $5 $(32) $122 $16 $153 $1 $(65) $105 Commodity held for sale (f) — — — — — 1 133 7 (63) 78 Total liabilities $3 $146 $5 $(32) $122 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $4 $7 $1 $6 $18 $1 $9 $8 $17 $35 Other (a)(b)(d) 200 108 — — 308 171 105 — — 276 Total assets $204 $115 $1 $6 $326 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $2 $126 $1 $(23) $106 $14 $129 $— $(57) $86 (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. There were no transfers between levels 1, 2 and 3 for the nine months ended September 30, 2016 and for the year ended December 31, 2015 . (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 September 30, 2016 and December 31, 2015 , 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) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet.
Schedule of Commodity Derivatives	The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at September 30, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $19.75-$80.00 per MWh 1 Discounted Cash Flow Forward capacity prices (a) $2.68-$9.45 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(0.14)-$2.82 per MWh Total Con Edison—Commodity $1 CECONY—Commodity Electricity $(1) Discounted Cash Flow Forward energy prices (a) $21.10-$80.00 per MWh Transmission Congestion Contracts $1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 52.8%-59.4% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (44.9)%-58.9% Total CECONY—Commodity $— (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 as of September 30, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of July 1, $5 $13 $2 $11 Included in earnings (4) (4) — (1) Included in regulatory assets and liabilities (5) (1) (3) (1) Purchases — 1 — 1 Sales (a) 4 — — — Settlements 1 (5) 1 (2) Ending balance as of September 30, $1 $4 $— $8 For the Nine Months Ended September 30, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (1) (18) (1) (5) Included in regulatory assets and liabilities (11) (1) (6) (1) Purchases 2 9 1 5 Sales (a) 4 — — — Settlements 1 (6) (2) (4) Ending balance as of September 30, $1 $4 $— $8 (a) Amounts represent derivative instruments novated as part of the assets of Con Edison Solutions’ retail electric supply business which were sold to a subsidiary of Exelon Corporation (see Note P).

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2016
Equity Method Investments and Joint Ventures [Abstract]
Summary of VIEs	The following table summarizes the VIEs in which Con Edison Development has entered into as of September 30, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $179 Panoche Valley (d) 120 20 2015 California 274 Mesquite Solar 1 83 20 2013 Arizona 107 Copper Mountain Solar 2 75 25 2013 Nevada 84 California Solar 55 25 2012 California 70 Broken Bow II 38 25 2014 Nebraska 51 Texas Solar 4 32 25 2014 Texas 43 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. 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 Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) In October 2016, Con Edison Development acquired the remaining 50 percent ownership interest in the project. See Note P.

General (Details)

General (Details)	9 Months Ended
	Sep. 30, 2016subsidiaryregistrant
Accounting Policies [Abstract]
Number of registrants | registrant	2
Number of regulated utility subsidiaries | subsidiary	2

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounting Policies [Abstract]
Net income	$ 497	$ 232	$ 310	$ 428	$ 219	$ 370	$ 1,039	$ 1,017
Weighted average common shares outstanding – basic	304.5			292.9			299.1	292.9
Add: Incremental shares attributable to effect of potentially dilutive securities	1.4			1.3			1.4	1.3
Adjusted weighted average common shares outstanding – diluted	305.9			294.2			300.5	294.2
Net income per common share-basic (dollars per share)	$ 1.63			$ 1.46			$ 3.47	$ 3.47
Net income per common share-diluted (dollars per share)	$ 1.62			$ 1.45			$ 3.46	$ 3.46

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Income/(Loss) by Component (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 13,958	$ 12,797	$ 13,061	$ 12,585
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2	7
Ending Balance	14,275	13,049	14,275	13,049
OCI before reclassifications, tax			1	(2)
Amounts reclassified from accumulated OCI related to pension plan liabilities, tax	(1)	(1)	(2)	(3)
CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	0	1	1	2
Accumulated Other Comprehensive Income/(Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(33)	(39)	(34)	(45)
OCI before reclassifications, net of tax			(1)	3
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	1	1	3	4
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	1	1	2	7
Ending Balance	(32)	(38)	(32)	(38)
Accumulated Other Comprehensive Income/(Loss) | CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(8)	(10)	(9)	(11)
OCI before reclassifications, net of tax			0	0
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	0	1	1	2
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	0	1	1	2
Ending Balance	$ (8)	$ (9)	$ (8)	$ (9)

Regulatory Matters - Summary of

Regulatory Matters - Summary of Rate Plan (Detail) - USD ($) $ in Millions	1 Months Ended		9 Months Ended	36 Months Ended
	Oct. 31, 2016	Apr. 30, 2016	Sep. 30, 2016	Dec. 31, 2019
CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Additional rate increase			$ 48
Deferrals for property taxes limitation from rates (percent)			90.00%
Deferrals for property taxes limitation from rates (percent)			80.00%
Maximum deferral (percentage)			30.00%
CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Additional rate increase			$ 41
New Jersey Board of Public Utilities | Rockland Electric Company | Year 1 | Rockland Electric Company | Electric
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount		$ 10
Return on common equity (percent)		10.20%
Common equity ratio (percent)		49.81%
Scenario, Forecast | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Public utilities, term of rate plan				3 years
Authorized return on common equity (percent)				9.00%
Earnings sharing (percentage)				9.50%
Common equity ratio (percent)				48.00%
Scenario, Forecast | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Public utilities, term of rate plan				3 years
Retention of revenues from non-firm customers (up to)				$ 65
Percentage of revenue reserve				15.00%
Authorized return on common equity (percent)				9.00%
Earnings sharing (percentage)				9.50%
Common equity ratio (percent)				48.00%
Scenario, Forecast | Year 1 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 195
Amortization to income of net regulatory (assets) and liabilities				84
Retention of annual transmission congestion revenues				75
Potential incentive revenue				28
Potential penalty expense				376
Average rate base				$ 18,902
Weighted average cost of capital (after-tax) (percent)				6.82%
Cost of long-term debt (percent)				4.93%
Additional rate increase				$ 199
Deferral, annual maximum (not more than) (percent)				0.10%
Scenario, Forecast | Year 1 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ (5)
Amortization to income of net regulatory (assets) and liabilities				39
Potential incentive revenue				7
Potential penalty expense				68
Average rate base				$ 4,841
Weighted average cost of capital (after-tax) (percent)				6.82%
Cost of long-term debt (percent)				4.93%
Scenario, Forecast | Year 2 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 155
Amortization to income of net regulatory (assets) and liabilities				83
Retention of annual transmission congestion revenues				75
Potential incentive revenue				47
Potential penalty expense				383
Average rate base				$ 19,530
Weighted average cost of capital (after-tax) (percent)				6.80%
Cost of long-term debt (percent)				4.88%
Additional rate increase				$ 199
Deferral, annual maximum (not more than) (percent)				0.075%
Scenario, Forecast | Year 2 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 92
Amortization to income of net regulatory (assets) and liabilities				37
Potential incentive revenue				8
Potential penalty expense				75
Average rate base				$ 5,395
Weighted average cost of capital (after-tax) (percent)				6.80%
Cost of long-term debt (percent)				4.88%
Scenario, Forecast | Year 3 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 155
Amortization to income of net regulatory (assets) and liabilities				69
Retention of annual transmission congestion revenues				75
Potential incentive revenue				64
Potential penalty expense				395
Average rate base				$ 20,277
Weighted average cost of capital (after-tax) (percent)				6.73%
Cost of long-term debt (percent)				4.74%
Additional rate increase				$ 199
Deferral, annual maximum (not more than) (percent)				0.05%
Scenario, Forecast | Year 3 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Base rate changes				$ 90
Amortization to income of net regulatory (assets) and liabilities				36
Potential incentive revenue				8
Potential penalty expense				83
Average rate base				$ 6,005
Weighted average cost of capital (after-tax) (percent)				6.73%
Cost of long-term debt (percent)				4.74%
Net plant target, excluding AMI | Scenario, Forecast | Year 1 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				$ 21,689
Net plant target, excluding AMI | Scenario, Forecast | Year 1 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				5,844
Net plant target, excluding AMI | Scenario, Forecast | Year 2 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				22,338
Net plant target, excluding AMI | Scenario, Forecast | Year 2 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				6,512
Net plant target, excluding AMI | Scenario, Forecast | Year 3 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				23,002
Net plant target, excluding AMI | Scenario, Forecast | Year 3 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				7,177
AMI | Scenario, Forecast | Year 1 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				126
AMI | Scenario, Forecast | Year 1 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				27
AMI | Scenario, Forecast | Year 2 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				257
AMI | Scenario, Forecast | Year 2 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				57
AMI | Scenario, Forecast | Year 3 | CECONY | Electric
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				415
AMI | Scenario, Forecast | Year 3 | CECONY | Gas
Public Utilities, General Disclosures [Line Items]
Average net utility plant rates				$ 100
Subsequent Event | New Jersey Board of Public Utilities | Rockland Electric Company | Year 1 | Rockland Electric Company | Electric
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	$ (4)
Return on common equity (percent)	10.20%
Common equity ratio (percent)	50.15%
Subsequent Event | New Jersey Board of Public Utilities | Rockland Electric Company | Year 2 | Rockland Electric Company | Electric
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amount	$ 6

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2016
Public Utilities, General Disclosures [Line Items]
Expected credit to customers				$ 116,000,000
Return on capital expenditures, not recoverable (up to)				55,000,000
Regulatory liabilities		$ 1,977,000,000		1,920,000,000
Prudence proceeding
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities		99,000,000		96,000,000
CECONY
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities		1,789,000,000		1,725,000,000
Requested deferral of incremental costs incurred to regulatory asset		35,000,000	$ 29,000,000
CECONY | Prudence proceeding
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities		$ 99,000,000		96,000,000
CECONY | June 2014 Plastic Fusion Proceeding
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities				$ 28,000,000
Scenario, Forecast | CECONY
Public Utilities, General Disclosures [Line Items]
Requested deferral of incremental costs incurred to regulatory asset	$ 37,000,000

Regulatory Matters - Regulatory

Regulatory Matters - Regulatory Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Regulatory assets
Regulatory assets – noncurrent	$ 7,544	$ 8,096
Regulatory assets – current	119	132
Total Regulatory Assets	7,663	8,228
Regulatory liabilities
Regulatory liabilities – noncurrent	1,920	1,977
Regulatory liabilities – current	123	115
Total Regulatory Liabilities	2,043	2,092
Allowance for cost of removal less salvage
Regulatory liabilities
Regulatory liabilities – noncurrent	713	676
Property tax reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	205	303
Pension and other postretirement benefit deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	163	76
Net unbilled revenue deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	121	109
Prudence proceeding
Regulatory liabilities
Regulatory liabilities – noncurrent	96	99
Unrecognized other postretirement costs
Regulatory liabilities
Regulatory liabilities – noncurrent	91	28
New York State income tax rate change
Regulatory liabilities
Regulatory liabilities – noncurrent	66	75
Base rate change deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	62	128
Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	60	70
Carrying charges on repair allowance and bonus depreciation
Regulatory liabilities
Regulatory liabilities – noncurrent	57	49
Earnings sharing - electric, gas and steam
Regulatory liabilities
Regulatory liabilities – noncurrent	34	80
Net utility plant reconciliations
Regulatory liabilities
Regulatory liabilities – noncurrent	27	32
Property tax refunds
Regulatory liabilities
Regulatory liabilities – noncurrent	12	44
World Trade Center settlement proceeds
Regulatory liabilities
Regulatory liabilities – noncurrent	5	21
Other
Regulatory liabilities
Regulatory liabilities – noncurrent	208	187
Revenue decoupling mechanism
Regulatory liabilities
Regulatory liabilities – current	74	45
Refundable energy costs
Regulatory liabilities
Regulatory liabilities – current	37	64
Deferred derivative gains
Regulatory liabilities
Regulatory liabilities – current	12	6
Unrecognized pension and other postretirement costs
Regulatory assets
Regulatory assets – noncurrent	3,369	3,876
Future income tax
Regulatory assets
Regulatory assets – noncurrent	2,429	2,350
Revenue taxes
Regulatory assets
Regulatory assets – noncurrent	298	253
Deferred storm costs
Regulatory assets
Regulatory assets – noncurrent	89	185
Deferred derivative losses
Regulatory assets
Regulatory assets – noncurrent	55	50
Unamortized loss on reacquired debt
Regulatory assets
Regulatory assets – noncurrent	45	50
Surcharge for New York State assessment
Regulatory assets
Regulatory assets – noncurrent	43	44
O&R property tax reconciliation
Regulatory assets
Regulatory assets – noncurrent	39	46
Pension and other postretirement benefits deferrals
Regulatory assets
Regulatory assets – noncurrent	34	45
Net electric deferrals
Regulatory assets
Regulatory assets – noncurrent	29	44
Preferred stock redemption
Regulatory assets
Regulatory assets – noncurrent	25	26
O&R transition bond charges
Regulatory assets
Regulatory assets – noncurrent	16	21
Recoverable energy costs
Regulatory assets
Regulatory assets – noncurrent	7	16
Regulatory assets – current	25	19
Other
Regulatory assets
Regulatory assets – noncurrent	228	175
Deferred derivative losses
Regulatory assets
Regulatory assets – current	94	113
CECONY
Regulatory assets
Regulatory assets – noncurrent	6,986	7,482
Regulatory assets – current	111	121
Total Regulatory Assets	7,097	7,603
Regulatory liabilities
Regulatory liabilities – noncurrent	1,725	1,789
Regulatory liabilities – current	96	84
Total Regulatory Liabilities	1,821	1,873
CECONY | Allowance for cost of removal less salvage
Regulatory liabilities
Regulatory liabilities – noncurrent	602	570
CECONY | Property tax reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	205	303
CECONY | Pension and other postretirement benefit deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	130	46
CECONY | Net unbilled revenue deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	121	109
CECONY | Prudence proceeding
Regulatory liabilities
Regulatory liabilities – noncurrent	96	99
CECONY | Unrecognized other postretirement costs
Regulatory liabilities
Regulatory liabilities – noncurrent	91	28
CECONY | New York State income tax rate change
Regulatory liabilities
Regulatory liabilities – noncurrent	64	72
CECONY | Base rate change deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	62	128
CECONY | Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	52	60
CECONY | Carrying charges on repair allowance and bonus depreciation
Regulatory liabilities
Regulatory liabilities – noncurrent	56	48
CECONY | Earnings sharing - electric, gas and steam
Regulatory liabilities
Regulatory liabilities – noncurrent	26	80
CECONY | Net utility plant reconciliations
Regulatory liabilities
Regulatory liabilities – noncurrent	27	31
CECONY | Property tax refunds
Regulatory liabilities
Regulatory liabilities – noncurrent	12	44
CECONY | World Trade Center settlement proceeds
Regulatory liabilities
Regulatory liabilities – noncurrent	5	21
CECONY | Other
Regulatory liabilities
Regulatory liabilities – noncurrent	176	150
CECONY | Revenue decoupling mechanism
Regulatory liabilities
Regulatory liabilities – current	70	45
CECONY | Refundable energy costs
Regulatory liabilities
Regulatory liabilities – current	18	33
CECONY | Deferred derivative gains
Regulatory liabilities
Regulatory liabilities – current	8	6
CECONY | Unrecognized pension and other postretirement costs
Regulatory assets
Regulatory assets – noncurrent	3,220	3,697
CECONY | Future income tax
Regulatory assets
Regulatory assets – noncurrent	2,312	2,232
CECONY | Revenue taxes
Regulatory assets
Regulatory assets – noncurrent	283	240
CECONY | Deferred storm costs
Regulatory assets
Regulatory assets – noncurrent	30	110
CECONY | Deferred derivative losses
Regulatory assets
Regulatory assets – noncurrent	49	46
CECONY | Unamortized loss on reacquired debt
Regulatory assets
Regulatory assets – noncurrent	43	48
CECONY | Surcharge for New York State assessment
Regulatory assets
Regulatory assets – noncurrent	40	40
CECONY | O&R property tax reconciliation
Regulatory assets
Regulatory assets – noncurrent	0	0
CECONY | Pension and other postretirement benefits deferrals
Regulatory assets
Regulatory assets – noncurrent	3	16
CECONY | Net electric deferrals
Regulatory assets
Regulatory assets – noncurrent	29	44
CECONY | Preferred stock redemption
Regulatory assets
Regulatory assets – noncurrent	25	26
CECONY | O&R transition bond charges
Regulatory assets
Regulatory assets – noncurrent	0	0
CECONY | Recoverable energy costs
Regulatory assets
Regulatory assets – noncurrent	5	15
Regulatory assets – current	24	18
CECONY | Other
Regulatory assets
Regulatory assets – noncurrent	212	157
CECONY | Deferred derivative losses
Regulatory assets
Regulatory assets – current	87	103
Superfund Sites
Regulatory assets
Total Regulatory Assets	823	904
Superfund Sites | Environmental remediation costs
Regulatory assets
Regulatory assets – noncurrent	823	904
Superfund Sites | CECONY
Regulatory assets
Total Regulatory Assets	720	800
Superfund Sites | CECONY | Environmental remediation costs
Regulatory assets
Regulatory assets – noncurrent	720	800
Workers’ compensation
Regulatory assets
Total Regulatory Assets	15	11
Workers’ compensation | Workers’ compensation
Regulatory assets
Regulatory assets – noncurrent	15	11
Workers’ compensation | CECONY
Regulatory assets
Total Regulatory Assets	15	11
Workers’ compensation | CECONY | Workers’ compensation
Regulatory assets
Regulatory assets – noncurrent	$ 15	$ 11

Capitalization - Carrying Amoun

Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Carrying Amount	$ 14,093	$ 12,745
Fair Value	16,325	13,856
CECONY
Debt Instrument [Line Items]
Carrying Amount	11,584	11,437
Fair Value	$ 13,564	$ 12,427

Capitalization - Additional Inf

Capitalization - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended	9 Months Ended
	Oct. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	May 31, 2016	Jun. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016	Feb. 29, 2016	Dec. 31, 2015
Schedule of Capitalization [Line Items]
Stock issued during the period, value					$ 702,000,000
Proceeds from long-term debt						$ 1,765,000,000	$ 238,000,000
Long-term debt, fair value		$ 16,325,000,000				16,325,000,000				$ 13,856,000,000
Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value		15,689,000,000				15,689,000,000
Level 3
Schedule of Capitalization [Line Items]
Long-term debt, fair value		636,000,000				636,000,000
CECONY
Schedule of Capitalization [Line Items]
Proceeds from long-term debt						550,000,000	$ 0
Long-term debt, fair value		13,564,000,000				13,564,000,000				$ 12,427,000,000
CECONY | Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value		12,928,000,000				12,928,000,000
CECONY | Level 3
Schedule of Capitalization [Line Items]
Long-term debt, fair value		$ 636,000,000				636,000,000
Tax-exempt debt						$ 636,000,000
Senior Notes | 4.21% Senior Notes due 2041 | Con Edison Development
Schedule of Capitalization [Line Items]
Debt Instrument, face amount									$ 218,000,000
Debt instrument, interest rate (percent)									4.21%
Senior Notes | 4.07% Senior Notes due 2036 | Con Edison Development
Schedule of Capitalization [Line Items]
Debt Instrument, face amount				$ 95,000,000
Debt instrument, interest rate (percent)				4.07%
Secured Debt | 2.00% Debentures due 2021
Schedule of Capitalization [Line Items]
Debt Instrument, face amount				$ 500,000,000
Debt instrument, interest rate (percent)				2.00%
Secured Debt | 3.85% Debentures due 2046 | CECONY
Schedule of Capitalization [Line Items]
Debt Instrument, face amount			$ 550,000,000		$ 550,000,000
Debt instrument, interest rate (percent)			3.85%		3.85%
Secured Debt | New Jersey Utility Agreement | Con Edison Solutions
Schedule of Capitalization [Line Items]
Debt instrument, interest rate (percent)			11.18%		11.18%
Proceeds from long-term debt			$ 2,000,000
Secured Debt | 5.50% Debentures due 2016 | CECONY
Schedule of Capitalization [Line Items]
Debt instrument, interest rate (percent)		5.50%				5.50%
Redemption of debt		$ 400,000,000
Unsecured Debt | Term Loan Credit Facility
Schedule of Capitalization [Line Items]
Debt Instrument, face amount			$ 400,000,000		$ 400,000,000
Common Stock
Schedule of Capitalization [Line Items]
Stock issued during period (in shares)				10,000,000	10,000,000
Stock issued during the period, value				$ 702,000,000	$ 1,000,000
LIBOR | Senior Notes | 4.07% Senior Notes due 2036 | Con Edison Development
Schedule of Capitalization [Line Items]
Debt instrument, basis spread on variable rate (percent)			1.00%
Scenario, Forecast | Secured Debt | 3.88% Debentures due 2016 | O&R
Schedule of Capitalization [Line Items]
Debt Instrument, face amount								$ 75,000,000
Debt instrument, interest rate (percent)								3.88%
Subsequent Event | Secured Debt | 5.45% Debentures due 2016 | O&R
Schedule of Capitalization [Line Items]
Debt instrument, interest rate (percent)	5.45%
Redemption of debt	$ 75,000,000

Short-Term Borrowing - Addition

Short-Term Borrowing - Additional Information (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 601,000,000	$ 1,529,000,000
Weighted average interest rate (percent)	0.70%	0.70%
Loans outstanding under credit agreement	$ 0	$ 0
Letters of credit outstanding under the Credit Agreement	2,000,000	15,000,000
CECONY
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 480,000,000	$ 1,033,000,000
Weighted average interest rate (percent)	0.70%	0.70%
Loans outstanding under credit agreement	$ 0	$ 0
Letters of credit outstanding under the Credit Agreement	$ 2,000,000

Pension Benefits - Total Period

Pension Benefits - Total Periodic Benefit Costs (Detail) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 69	$ 74	$ 207	$ 223
Interest cost on projected benefit obligation	149	144	447	431
Expected return on plan assets	(237)	(222)	(711)	(664)
Recognition of net actuarial loss	149	194	447	581
Recognition of prior service costs	1	1	3	3
NET PERIODIC BENEFIT COST	131	191	393	574
Amortization of regulatory asset	0	1	0	2
TOTAL PERIODIC BENEFIT COST	131	192	393	576
Cost capitalized	(51)	(80)	(157)	(224)
Reconciliation to rate level	10	(14)	35	(56)
Cost charged to operating expenses	90	98	271	296
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	65	70	194	209
Interest cost on projected benefit obligation	140	135	419	404
Expected return on plan assets	(225)	(210)	(674)	(630)
Recognition of net actuarial loss	141	183	424	550
Recognition of prior service costs	0	0	1	1
NET PERIODIC BENEFIT COST	121	178	364	534
Amortization of regulatory asset	0	1	0	2
TOTAL PERIODIC BENEFIT COST	121	179	364	536
Cost capitalized	(49)	(76)	(148)	(214)
Reconciliation to rate level	13	(14)	39	(56)
Cost charged to operating expenses	$ 85	$ 89	$ 255	$ 266

Pension Benefits - Additional I

Pension Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 508
Contributions	504
CECONY | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	469
Contributions	466
CECONY | Non-qualified Supplemental Plan
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 17

Other Postretirement Benefits -

Other Postretirement Benefits - Total Periodic Postretirement Benefit Costs (Detail) - Other Postretirement Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5	$ 13	$ 15
Interest cost on accumulated other postretirement benefit obligation	12	13	36	38
Expected return on plan assets	(19)	(20)	(58)	(59)
Recognition of net actuarial loss	1	8	4	24
Recognition of prior service cost	(5)	(5)	(15)	(15)
NET PERIODIC BENEFIT COST	(7)	1	(20)	3
Cost capitalized	2	(1)	5	(2)
Reconciliation to rate level	7	4	20	12
Cost charged to operating expenses	2	4	5	13
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	4	10	11
Interest cost on accumulated other postretirement benefit obligation	10	11	30	32
Expected return on plan assets	(17)	(17)	(50)	(51)
Recognition of net actuarial loss	1	7	2	21
Recognition of prior service cost	(3)	(4)	(11)	(10)
NET PERIODIC BENEFIT COST	(6)	1	(19)	3
Cost capitalized	2	(1)	5	(2)
Reconciliation to rate level	6	2	19	5
Cost charged to operating expenses	$ 2	$ 2	$ 5	$ 6

Other Postretirement Benefits49

Other Postretirement Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 6

Environmental Matters - Accrued

Environmental Matters - Accrued Liabilities and Regulatory Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Accrued Liabilities:
Accrued Liabilities	$ 752	$ 765
Regulatory assets	7,663	8,228
Manufactured gas plant sites
Accrued Liabilities:
Accrued Liabilities	664	679
Other Superfund Sites
Accrued Liabilities:
Accrued Liabilities	88	86
Superfund Sites
Accrued Liabilities:
Accrued Liabilities	752	765
Regulatory assets	823	904
CECONY
Accrued Liabilities:
Accrued Liabilities	661	665
Regulatory assets	7,097	7,603
CECONY | Manufactured gas plant sites
Accrued Liabilities:
Accrued Liabilities	574	579
CECONY | Other Superfund Sites
Accrued Liabilities:
Accrued Liabilities	87	86
CECONY | Superfund Sites
Accrued Liabilities:
Accrued Liabilities	661	665
Regulatory assets	$ 720	$ 800

Environmental Matters - Environ

Environmental Matters - Environmental Remediation Costs (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 8	$ 6	$ 20	$ 21
CECONY
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 5	$ 6	$ 10	$ 18

Environmental Matters - Additio

Environmental Matters - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Site Contingency [Line Items]
Insurance recoveries	$ 1,000,000	$ 0	$ 1,000,000	$ 0
Manufactured gas plant sites | Maximum
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)					$ 2,800,000,000
CECONY
Site Contingency [Line Items]
Insurance recoveries	$ 1,000,000	$ 0	$ 1,000,000	$ 0
CECONY | Manufactured gas plant sites | Maximum
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)					$ 2,700,000,000
Asbestos Related
Site Contingency [Line Items]
Estimated undiscounted asbestos liability (years)			15 years
Asbestos Related | CECONY
Site Contingency [Line Items]
Estimated undiscounted asbestos liability (years)			15 years

Environmental Matters - Accru53

Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Site Contingency [Line Items]
Regulatory assets	$ 7,663	$ 8,228
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers’ compensation
Site Contingency [Line Items]
Accrued liability	90	86
Regulatory assets	15	11
CECONY
Site Contingency [Line Items]
Regulatory assets	7,097	7,603
CECONY | Asbestos Suits
Site Contingency [Line Items]
Accrued liability	7	7
Regulatory assets	7	7
CECONY | Workers’ compensation
Site Contingency [Line Items]
Accrued liability	85	81
Regulatory assets	$ 15	$ 11

Other Material Contingencies -

Other Material Contingencies - Additional Information (Detail)	Mar. 12, 2014buildingPerson	Jul. 31, 2007Person	Sep. 30, 2016USD ($)lawsuit	Dec. 31, 2015USD ($)	Dec. 31, 2014
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			$ 2,422,000,000	$ 2,856,000,000
Ownership interest, percentage					45.70%
Estimated project cost percentage			175.00%
Manhattan Steam Main Rupture
Guarantor Obligations [Line Items]
Number of person died in steam ruptured | Person		1
Number of suits pending against the company | lawsuit			60
Estimated accrued liability for suits			$ 30,000,000
Insurance receivable			$ 39,000,000
Manhattan Explosion and Fire
Guarantor Obligations [Line Items]
Number of suits pending against the company | lawsuit			70
Number of buildings destroyed by fire | building	2
Number of people died in explosion and fire incident | Person	8
Number of people injured in explosion and fire incident | Person	50
Financial And Performance Guarantee For CET Gas
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			$ 25,000,000
Financial And Performance Guarantee During Period in which Con Edison Solutions Provides Transition Services
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			123,000,000
Financial and Performance Guarantee, Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			128,000,000
Indemnity agreements amount			70,000,000
Electric provider obligation to Public Utility Commission of Texas			5,000,000
Finance and Performance Guarantee for Consolidated Edison Solutions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			$ 53,000,000

Other Material Contingencies 55

Other Material Contingencies - Total Guarantees (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,422	$ 2,856
Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	1,048
Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	783
Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	463
Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	128
0-3 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	1,826
0-3 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	618
0-3 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	635
0-3 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	445
0-3 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	128
4-10 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	487
4-10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	430
4-10 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	57
4-10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	0
4-10 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	0
Greater than 10 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	109
Greater than 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	0
Greater than 10 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	91
Greater than 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	18
Greater than 10 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 0

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Taxes Disclosure [Line Items]
Income taxes on operating income		$ 314	$ 249	$ 602	$ 548
Effective tax rate		39.00%	37.00%	37.00%	35.00%
Estimated liability for uncertain tax positions		$ 37		$ 37
Uncertain tax positions, reasonably possible to resolve within twelve months		29		29
Uncertain tax positions, reasonably possible to resolve within twelve months, net of federal taxes		20		20
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate		37		37
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate, net of federal taxes		25		25
CECONY
Income Taxes Disclosure [Line Items]
Income taxes on operating income		$ 226	$ 222	$ 491	$ 515
Effective tax rate		37.00%	37.00%	36.00%	35.00%
Estimated liability for uncertain tax positions		$ 5		$ 5
Uncertain tax positions, reasonably possible to resolve within twelve months		5		5
Uncertain tax positions, reasonably possible to resolve within twelve months, net of federal taxes		4		4
Subsequent Event
Income Taxes Disclosure [Line Items]
Income tax refund received	$ 19
Tax Year 2015 | Subsequent Event
Income Taxes Disclosure [Line Items]
Income taxes refund	$ 16
Tax Year 2016
Income Taxes Disclosure [Line Items]
Income taxes refund		$ 32		$ 32

Financial Information by Busi57

Financial Information by Business Segment - Financial Data for Business Segments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operating revenues	$ 3,417	$ 3,443	$ 9,368	$ 9,847
Depreciation and amortization	305	285	905	840
Operating income	940	830	2,097	2,028
Other income (deductions)	49	9	61	23
Interest charges	178	162	517	486
Income taxes on operating income	321	260	620	574
Total assets	47,316	44,971	47,316	44,971	$ 45,642
Construction expenditures	818	874	2,579	2,473
CECONY
Segment Reporting Information [Line Items]
Operating revenues	2,828	2,829	7,741	8,122
Depreciation and amortization	278	262	825	773
Operating income	766	745	1,799	1,889
Other income (deductions)	2	(3)	2	(4)
Interest charges	154	145	451	435
Income taxes on operating income	234	225	503	525
Total assets	40,436	39,670	40,436	39,670	$ 40,230
Construction expenditures	659	624	1,796	1,696
CECONY | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	217	207	645	610
Operating income	841	811	1,487	1,511
Other income (deductions)	2	(2)	3	(3)
Interest charges	117	111	342	333
Income taxes on operating income	275	260	412	401
Total assets	30,580	30,369	30,580	30,369
Construction expenditures	411	419	1,133	1,165
CECONY | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	41	35	118	105
Operating income	(28)	(17)	273	278
Other income (deductions)	0	(1)	(1)	(1)
Interest charges	27	24	79	71
Income taxes on operating income	(24)	(17)	73	82
Total assets	7,300	6,687	7,300	6,687
Construction expenditures	224	178	589	466
CECONY | Steam
Segment Reporting Information [Line Items]
Depreciation and amortization	20	20	62	58
Operating income	(47)	(49)	39	100
Other income (deductions)	0	0	0	0
Interest charges	10	10	30	31
Income taxes on operating income	(17)	(18)	18	42
Total assets	2,556	2,614	2,556	2,614
Construction expenditures	24	27	74	65
O&R
Segment Reporting Information [Line Items]
Depreciation and amortization	17	17	50	51
Operating income	48	42	114	85
Other income (deductions)	1	(5)	1	(4)
Interest charges	9	9	28	27
Income taxes on operating income	16	12	35	22
Total assets	2,784	2,713	2,784	2,713
Construction expenditures	38	38	106	101
O&R | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	12	13	37	38
Operating income	55	51	86	85
Other income (deductions)	1	(4)	1	(2)
Interest charges	6	6	19	18
Income taxes on operating income	20	17	27	26
Total assets	1,985	1,959	1,985	1,959
Construction expenditures	24	26	70	72
O&R | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	5	4	13	13
Operating income	(7)	(9)	28	0
Other income (deductions)	0	(1)	0	(2)
Interest charges	3	3	9	9
Income taxes on operating income	(4)	(5)	8	(4)
Total assets	799	754	799	754
Construction expenditures	14	12	36	29
Competitive energy businesses
Segment Reporting Information [Line Items]
Depreciation and amortization	11	6	30	16
Operating income	125	43	184	53
Other income (deductions)	27	17	36	33
Interest charges	7	2	23	5
Income taxes on operating income	67	21	76	24
Total assets	2,394	1,547	2,394	1,547
Construction expenditures	121	212	677	676
Con Edison Transmission
Segment Reporting Information [Line Items]
Operating income	(1)	0	(1)	0
Other income (deductions)	20	0	23	0
Interest charges	3	0	4	0
Income taxes on operating income	0	0	0	0
Total assets	1,072	2	1,072	2
Construction expenditures	0	0	0	0
Other
Segment Reporting Information [Line Items]
Depreciation and amortization	(1)	0	0	0
Operating income	2	0	1	1
Other income (deductions)	(1)	0	(1)	(2)
Interest charges	5	6	11	19
Income taxes on operating income	4	2	6	3
Total assets	630	1,039	630	1,039
Construction expenditures	0	0	0	0
Operating revenues
Segment Reporting Information [Line Items]
Operating revenues	3,417	3,443	9,368	9,847
Operating revenues | CECONY
Segment Reporting Information [Line Items]
Operating revenues	2,828	2,829	7,741	8,122
Operating revenues | CECONY | Electric
Segment Reporting Information [Line Items]
Operating revenues	2,557	2,558	6,222	6,416
Operating revenues | CECONY | Gas
Segment Reporting Information [Line Items]
Operating revenues	208	213	1,113	1,177
Operating revenues | CECONY | Steam
Segment Reporting Information [Line Items]
Operating revenues	63	58	406	529
Operating revenues | O&R
Segment Reporting Information [Line Items]
Operating revenues	240	229	630	640
Operating revenues | O&R | Electric
Segment Reporting Information [Line Items]
Operating revenues	213	205	497	523
Operating revenues | O&R | Gas
Segment Reporting Information [Line Items]
Operating revenues	27	24	133	117
Operating revenues | Competitive energy businesses
Segment Reporting Information [Line Items]
Operating revenues	350	386	998	1,087
Operating revenues | Other
Segment Reporting Information [Line Items]
Operating revenues	(1)	(1)	(1)	(2)
Inter-segment revenues | CECONY
Segment Reporting Information [Line Items]
Operating revenues	(28)	(27)	(82)	(82)
Inter-segment revenues | CECONY | Electric
Segment Reporting Information [Line Items]
Operating revenues	5	4	13	13
Inter-segment revenues | CECONY | Gas
Segment Reporting Information [Line Items]
Operating revenues	1	1	4	4
Inter-segment revenues | CECONY | Steam
Segment Reporting Information [Line Items]
Operating revenues	22	22	65	65
Inter-segment revenues | Competitive energy businesses
Segment Reporting Information [Line Items]
Operating revenues	(2)	(2)	7	(5)
Inter-segment revenues | Other
Segment Reporting Information [Line Items]
Operating revenues	$ 2	$ 2	$ (7)	$ 5

Derivative Instruments and He58

Derivative Instruments and Hedging Activities - Fair Values of Commodity Derivatives Including Offsetting of Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	$ 133	$ 182
Gross Amounts Offset	(117)	(160)
Net Amounts of Assets/ (Liabilities)	16	22
Gross Amounts of Recognized Assets/(Liabilities)	(254)	(389)
Gross Amounts Offset	132	206
Net Amounts of Assets/ (Liabilities)	(122)	(183)
Gross Amounts of Recognized Assets/(Liabilities)	(121)	(207)
Gross Amounts Offset	15	46
Net Amounts of Assets/ (Liabilities)	(106)	(161)
Margin deposits	12	26
Fair Value of Derivative Assets, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	75	59
Gross Amounts Offset	(60)	(41)
Net Amounts of Assets/ (Liabilities)	15	18
Fair Value of Derivative Assets, Assets Held for Sale, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	0	51
Gross Amounts Offset	0	(50)
Net Amounts of Assets/ (Liabilities)	0	1
Fair Value of Derivative Assets, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	58	57
Gross Amounts Offset	(57)	(54)
Net Amounts of Assets/ (Liabilities)	1	3
Fair Value of Derivative Assets, Assets Held for Sale, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	0	15
Gross Amounts Offset	0	(15)
Net Amounts of Assets/ (Liabilities)	0	0
Fair Value of Derivative Liabilities, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(143)	(144)
Gross Amounts Offset	73	78
Net Amounts of Assets/ (Liabilities)	(70)	(66)
Fair Value of Derivative Liabilities, Liabilities Held For Sale, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	0	(115)
Gross Amounts Offset	0	50
Net Amounts of Assets/ (Liabilities)	0	(65)
Fair Value of Derivative Liabilities, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(111)	(102)
Gross Amounts Offset	59	63
Net Amounts of Assets/ (Liabilities)	(52)	(39)
Fair Value of Derivative Liabilities, Liabilities Held For Sale, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	0	(28)
Gross Amounts Offset	0	15
Net Amounts of Assets/ (Liabilities)	0	(13)
CECONY
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	97	88
Gross Amounts Offset	(91)	(79)
Net Amounts of Assets/ (Liabilities)	6	9
Gross Amounts of Recognized Assets/(Liabilities)	(214)	(213)
Gross Amounts Offset	108	127
Net Amounts of Assets/ (Liabilities)	(106)	(86)
Gross Amounts of Recognized Assets/(Liabilities)	(117)	(125)
Gross Amounts Offset	17	48
Net Amounts of Assets/ (Liabilities)	(100)	(77)
Margin deposits	12	26
CECONY | Fair Value of Derivative Assets, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	52	40
Gross Amounts Offset	(46)	(32)
Net Amounts of Assets/ (Liabilities)	6	8
CECONY | Fair Value of Derivative Assets, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	45	48
Gross Amounts Offset	(45)	(47)
Net Amounts of Assets/ (Liabilities)	0	1
CECONY | Fair Value of Derivative Liabilities, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(122)	(121)
Gross Amounts Offset	61	71
Net Amounts of Assets/ (Liabilities)	(61)	(50)
CECONY | Fair Value of Derivative Liabilities, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(92)	(92)
Gross Amounts Offset	47	56
Net Amounts of Assets/ (Liabilities)	$ (45)	$ (36)

Derivative Instruments and He59

Derivative Instruments and Hedging Activities - Realized and Unrealized Gains or Losses on Commodity Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ (3)	$ (1)	$ 5	$ 0
Total deferred gains/(losses)	(75)	(31)	(149)	(59)
Net deferred gains/(losses)	(78)	(32)	(144)	(59)
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(77)	(52)	(163)	(134)
Deferred Derivative Gains, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(1)	(1)	6	0
Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(2)	0	(1)	0
Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(19)	8	19	40
Recoverable energy costs
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(39)	(53)	(163)	(92)
Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(17)	14	(5)	(7)
CECONY
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(3)	(1)	1	1
Total deferred gains/(losses)	(67)	(28)	(135)	(52)
Net deferred gains/(losses)	(70)	(29)	(134)	(51)
CECONY | Deferred Derivative Gains, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(3)	(1)	2	1
CECONY | Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	0	0	(1)	0
CECONY | Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(18)	8	16	40
CECONY | Recoverable energy costs
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(35)	(49)	(148)	(87)
CECONY | Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(14)	13	(3)	(5)
Non Utility Operating Revenue
Pre-tax gain/(loss) recognized in income
Unrealized gain (loss) on derivatives	(2)		(3)	(3)
Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(37)	(31)	(106)	(60)
Unrealized gain (loss) on derivatives	(23)	12	11	6
Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(38)	(26)	(72)	(94)
Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	$ (2)	$ 5	$ 15	$ 20

Derivative Instruments and He60

Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Detail)	9 Months Ended
	Sep. 30, 2016DTHMWhMWgal
Electric Energy Derivative
Derivatives, Fair Value [Line Items]
Electric Energy (MWH) | MWh	22,797,395
Electric Capacity Derivative
Derivatives, Fair Value [Line Items]
Capacity (MW) | MW	15,472
Natural Gas Derivative
Derivatives, Fair Value [Line Items]
Natural Gas (Dt) | DTH	69,954,738
Refined Fuels
Derivatives, Fair Value [Line Items]
Refined fuel (gallons) | gal	1,344,000
CECONY | Electric Energy Derivative
Derivatives, Fair Value [Line Items]
Electric Energy (MWH) | MWh	20,724,225
CECONY | Electric Capacity Derivative
Derivatives, Fair Value [Line Items]
Capacity (MW) | MW	9,000
CECONY | Natural Gas Derivative
Derivatives, Fair Value [Line Items]
Natural Gas (Dt) | DTH	70,100,000
CECONY | Refined Fuels
Derivatives, Fair Value [Line Items]
Refined fuel (gallons) | gal	1,344,000

Derivative Instruments and He61

Derivative Instruments and Hedging Activities - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 141
Makeup of net credit exposure with commodity exchange brokers	20
Makeup of net credit exposure independent system operators	77
Makeup of net credit exposure with investment-grade counterparties	34
Makeup of net credit exposure non-investment grade/non-rated counterparties	10
CECONY
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	13
Makeup of net credit exposure with commodity exchange brokers	12
Makeup of net credit exposure with investment-grade counterparties	$ 1

Derivative Instruments and He62

Derivative Instruments and Hedging Activities - Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features (Detail) $ in Millions	Sep. 30, 2016USD ($)
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	$ 111
Collateral posted	24
Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	18
Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	106
Derivatives in net asset position additional collateral	9
Additional Collateral Required Due To Loss Of Unsecured Credit
Derivatives, Fair Value [Line Items]
Collateral posted	10
CECONY
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	97
Collateral posted	23
CECONY | Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	15
CECONY | Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	$ 84

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 16	$ 22
Derivative liabilities	122	183
CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	9
Derivative liabilities	106	86
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	365	345
Total liabilities	122	183
Recurring | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	326	311
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	230	187
Total liabilities	3	17
Recurring | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	204	172
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	134	200
Total liabilities	146	286
Recurring | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	115	114
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	6	14
Total liabilities	5	8
Recurring | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	28	47
Derivative liabilities	122	105
Recurring | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	18	35
Derivative liabilities	106	86
Recurring | Commodity | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	2
Derivative liabilities	3	16
Recurring | Commodity | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	4	1
Derivative liabilities	2	14
Recurring | Commodity | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	21	25
Derivative liabilities	146	153
Recurring | Commodity | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	7	9
Derivative liabilities	126	129
Recurring | Commodity | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	13
Derivative liabilities	5	1
Recurring | Commodity | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1	8
Total assets	1	8
Derivative liabilities	1	0
Recurring | Commodity Contract, Held For Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	1
Derivative liabilities	0	78
Recurring | Commodity Contract, Held For Sale | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	1
Recurring | Commodity Contract, Held For Sale | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	63
Derivative liabilities	0	133
Recurring | Commodity Contract, Held For Sale | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	1
Derivative liabilities	0	7
Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	337	297
Recurring | Other | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	308	276
Recurring | Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	224	185
Recurring | Other | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	200	171
Recurring | Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	113	112
Recurring | Other | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	108	105
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
Recurring | Netting Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	(5)	(56)
Total liabilities	(32)	(128)
Recurring | Netting Adjustments | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(5)	7
Derivative liabilities	(32)	(65)
Recurring | Netting Adjustments | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	17
Total assets	6	17
Derivative liabilities	(23)	(57)
Recurring | Netting Adjustments | Commodity Contract, Held For Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	(63)
Derivative liabilities	0	(63)
Recurring | Netting Adjustments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Recurring | Netting Adjustments | Other | 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 (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)$ / MWh$ / kW-month
Transmission Congestion Contracts/Financial Transmission Rights
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Forward Capacity Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Minimum | Discount to adjust auction prices for inter-zonal forward price curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	52.80%
Minimum | Discount/premium to adjust auction prices for historical monthly realized settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	(44.90%)
Minimum | Inter-zonal forward price curves adjusted for historical zonal losses
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	(0.14)
Minimum | Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	19.75
Minimum | Forward Capacity Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / kW-month	2.68
Maximum | Discount to adjust auction prices for inter-zonal forward price curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	59.40%
Maximum | Discount/premium to adjust auction prices for historical monthly realized settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	58.90%
Maximum | Inter-zonal forward price curves adjusted for historical zonal losses
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	2.82
Maximum | Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	80
Maximum | Forward Capacity Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / kW-month	9.45
Level 3
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 1
Level 3 | Transmission Congestion Contracts/Financial Transmission Rights
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	1
Level 3 | Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	(1)
Level 3 | Forward Capacity Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 1
CECONY | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
CECONY | Transmission Congestion Contracts
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
CECONY | Minimum | Discount to adjust auction prices for inter-zonal forward price curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	52.80%
CECONY | Minimum | Discount/premium to adjust auction prices for historical monthly realized settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	(44.90%)
CECONY | Minimum | Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	21.10
CECONY | Maximum | Discount to adjust auction prices for inter-zonal forward price curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	59.40%
CECONY | Maximum | Discount/premium to adjust auction prices for historical monthly realized settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	58.90%
CECONY | Maximum | Forward Energy Prices | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	80
CECONY | Level 3
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 0
CECONY | Level 3 | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	(1)
CECONY | Level 3 | Transmission Congestion Contracts
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives	$ 1

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 5	$ 13	$ 6	$ 20
Included in earnings	(4)	(4)	(1)	(18)
Included in regulatory assets and liabilities	(5)	(1)	(11)	(1)
Purchases	0	1	2	9
Sales	4	0	4	0
Settlements	1	(5)	1	(6)
Ending balance	1	4	1	4
CECONY
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2	11	8	13
Included in earnings	0	(1)	(1)	(5)
Included in regulatory assets and liabilities	(3)	(1)	(6)	(1)
Purchases	0	1	1	5
Sales	0	0	0	0
Settlements	1	(2)	(2)	(4)
Ending balance	$ 0	$ 8	$ 0	$ 8

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Purchased power expense
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, assets measured on recurring basis, change in unrealized gain (loss)	$ (4)	$ (3)	$ (2)	$ (8)
Competitive energy businesses
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) on Level 3 energy derivative liabilities	$ (5)	$ (3)	$ (6)	$ (12)

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail) - CECONY	12 Months Ended
	Dec. 31, 2015entitycounterparty
Variable Interest Entity [Line Items]
Number of potential VIEs, long-term electricity purchase agreements | entity	2
Number of counterparties | counterparty	2

Variable Interest Entities - Su

Variable Interest Entities - Summary of VIEs (Detail)	9 Months Ended
	Sep. 30, 2016USD ($)MW	Oct. 31, 2016
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Percentage of variable interests	50.00%
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 3 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	128
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 179,000,000
Variable Interest Entity, Not Primary Beneficiary | Panoche Valley | California
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	120
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,015
Maximum exposure to loss	$ 274,000,000
Variable Interest Entity, Not Primary Beneficiary | Mesquite Solar 1 | Arizona
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	83
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,013
Maximum exposure to loss	$ 107,000,000
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 2 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	75
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,013
Maximum exposure to loss	$ 84,000,000
Variable Interest Entity, Not Primary Beneficiary | California Solar | California
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	55
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,012
Maximum exposure to loss	$ 70,000,000
Variable Interest Entity, Not Primary Beneficiary | Broken Bow II | Nebraska
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	38
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 51,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4
Variable Interest Entity [Line Items]
Percentage of variable interests	80.00%
VIEs, noncontrolling interest	$ 8,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4 | Texas
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	32
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 43,000,000
Scenario, Forecast | Panoche Valley | California
Variable Interest Entity [Line Items]
Voting interest acquired (percentage)		50.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Oct. 31, 2016	Jun. 30, 2016	May 31, 2016	Jan. 31, 2016	Dec. 31, 2014
Related Party Transaction [Line Items]
Ownership interest, percentage										45.70%
Costs of gas purchased	$ 81	$ 64		$ 320	$ 415
Loss on derivative	77	52		163	134
CECONY | Financial Electric Capacity Contract
Related Party Transaction [Line Items]
Loss on derivative	1			1
CECONY
Related Party Transaction [Line Items]
Costs of gas purchased	34	$ 30		217	$ 282
CET Electric
Related Party Transaction [Line Items]
Ownership interest, percentage								45.70%	45.70%
Stagecoach Gas Services LLC
Related Party Transaction [Line Items]
Equity method ownership (percent)							50.00%
Stagecoach Gas Services LLC | CECONY | Equity Method Investee | Purchased Power Costs
Related Party Transaction [Line Items]
Costs of gas purchased	10		$ 8
Panoche Valley | Equity Method Investee
Related Party Transaction [Line Items]
Notes receivable from related parties	$ 234		$ 234	$ 234
Equity method ownership (percent)	50.00%		50.00%	50.00%
California | Scenario, Forecast | Panoche Valley
Related Party Transaction [Line Items]
Voting interest acquired (percentage)						50.00%
California | Scenario, Forecast | Panoche Valley
Related Party Transaction [Line Items]
Voting interest acquired (percentage)						50.00%

Acquisitions, Investments and70

Acquisitions, Investments and Dispositions - Additional Information (Details) $ in Millions	Sep. 30, 2015USD ($)	Oct. 31, 2016USD ($)MW	Sep. 30, 2016USD ($)	Aug. 31, 2016USD ($)	Jun. 30, 2016USD ($)	May 31, 2016USD ($)	Jan. 31, 2016USD ($)MW	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)MW	Sep. 30, 2015USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage														45.70%
Non-utility property			$ 1,127					$ 1,127		$ 1,127			$ 832
Other current assets			206					206		206			191
Gain on sale of business								104	$ 0	104	$ 0
Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership (percent)							12.50%
Payments to acquire equity method investments							$ 18
Equity method investments			41					41		41
Stagecoach Gas Services LLC
Schedule of Equity Method Investments [Line Items]
Equity method ownership (percent)					50.00%
Payments to acquire equity method investments					$ 945
Equity method investments			968					968		$ 968
Pilesgrove
Schedule of Equity Method Investments [Line Items]
Equity method ownership (percent)					50.00%
Impairment of investment					$ 8
Impairment of investment, net of tax					$ 5
New Jersey | Pilesgrove
Schedule of Equity Method Investments [Line Items]
Generating capacity | MW										18
Texas Solar 7 | Texas
Schedule of Equity Method Investments [Line Items]
Voting interest acquired (percentage)							100.00%
Generating capacity | MW							106
Payments to acquire business							$ 227
Non-utility construction work in progress							218
Other receivables							$ 9
Pilesgrove
Schedule of Equity Method Investments [Line Items]
Voting interest acquired (percentage)				50.00%
Net assets of project			48					48		$ 48
Non-utility property			45					45		45
Consideration transferred				$ 16
Bargain purchase gain				8
Bargain purchase gain, net of tax				5
Other current assets			3					3		3
Electric | Texas Solar 7 | Texas
Schedule of Equity Method Investments [Line Items]
Net assets of project			123					123		123
Scenario, Forecast | Panoche Valley | California
Schedule of Equity Method Investments [Line Items]
Voting interest acquired (percentage)		50.00%
Generating capacity | MW		240
Consideration transferred		$ 37
Scenario, Forecast | Gas | Minimum | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments												$ 3,000
Scenario, Forecast | Gas | Maximum | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments												$ 3,500
CET Electric
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage						45.70%	45.70%
CET Electric | NY Transco
Schedule of Equity Method Investments [Line Items]
Equity method investments			53					$ 53		$ 53
Purchase Price of TOTS Project Transfer | NY Transco | CET Electric
Schedule of Equity Method Investments [Line Items]
Related party transaction, amount of transaction						$ 122
Lease Payments | NY Transco | CET Electric
Schedule of Equity Method Investments [Line Items]
Expenses from transactions with related party						$ 8
Discontinued Operations, Held-for-sale | Pike
Schedule of Equity Method Investments [Line Items]
Impairment of long-lived assets to be disposed of	$ 5
Impairment of long-lived assets to be disposed of, net of taxes	$ 3
Assets held for sale													23
Liabilities held for sale													5
Discontinued Operations, Held-for-sale | Retail Electric Supply Business
Schedule of Equity Method Investments [Line Items]
Assets held for sale													134
Liabilities held for sale													$ 84
Discontinued Operations, Disposed of by Sale | Pike
Schedule of Equity Method Investments [Line Items]
Proceeds from divestiture of business				$ 15
Discontinued Operations, Disposed of by Sale | Pike | O&R
Schedule of Equity Method Investments [Line Items]
Period for transition services (up to)				18 months
Agreement to purchase and sell, term				3 years
Agreement to purchase and sell, term of extension option				3 years
Discontinued Operations, Disposed of by Sale | Retail Electric Supply Business
Schedule of Equity Method Investments [Line Items]
Proceeds from divestiture of business			235
Gain on sale of business			104
Gain on sale of business, after tax			47
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			29
Tax effect of sale, state tax related to change in apportionment of state income taxes, net of federal tax			$ 19