Consolidated Edison Co Of New York 10-Q 4 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
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		305,379,901
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
	Mar. 31, 2017	Mar. 31, 2016
OPERATING REVENUES
Electric	$ 1,934	$ 1,912
Gas	862	676
Steam	298	258
Non-utility	134	310
TOTAL OPERATING REVENUES	3,228	3,156
OPERATING EXPENSES
Purchased power	385	691
Fuel	100	71
Gas purchased for resale	321	158
Other operations and maintenance	780	787
Depreciation and amortization	329	297
Taxes, other than income taxes	542	510
TOTAL OPERATING EXPENSES	2,457	2,514
OPERATING INCOME	771	642
OTHER INCOME (DEDUCTIONS)
Investment income	19	0
Other income	5	4
Allowance for equity funds used during construction	2	2
Other deductions	(1)	(5)
TOTAL OTHER INCOME (DEDUCTIONS)	25	1
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	796	643
INTEREST EXPENSE
Interest on long-term debt	178	163
Other interest	4	7
Allowance for borrowed funds used during construction	(1)	(1)
NET INTEREST EXPENSE	181	169
INCOME BEFORE INCOME TAX EXPENSE	615	474
INCOME TAX EXPENSE	227	164
NET INCOME	$ 388	$ 310
Net income per common share-basic (dollars per share)	$ 1.27	$ 1.05
Net income per common share-diluted (dollars per share)	1.27	1.05
DIVIDENDS DECLARED PER COMMON SHARE (dollars per share)	$ 0.69	$ 0.67
AVERAGE NUMBER OF SHARES OUTSTANDING-BASIC (IN MILLIONS) (shares)	305.1	293.7
AVERAGE NUMBER OF SHARES OUTSTANDING—DILUTED (IN MILLIONS) (shares)	306.3	294.8
CECONY
OPERATING REVENUES
Electric	$ 1,793	$ 1,773
Gas	765	601
Steam	298	258
TOTAL OPERATING REVENUES	2,856	2,632
OPERATING EXPENSES
Purchased power	348	352
Fuel	100	71
Gas purchased for resale	230	132
Other operations and maintenance	664	681
Depreciation and amortization	294	272
Taxes, other than income taxes	515	484
TOTAL OPERATING EXPENSES	2,151	1,992
OPERATING INCOME	705	640
OTHER INCOME (DEDUCTIONS)
Investment income	4	1
Allowance for equity funds used during construction	2	2
Other deductions	(1)	(5)
TOTAL OTHER INCOME (DEDUCTIONS)	5	(2)
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	710	638
INTEREST EXPENSE
Interest on long-term debt	150	144
Other interest	4	5
Allowance for borrowed funds used during construction	(1)	(1)
NET INTEREST EXPENSE	153	148
INCOME BEFORE INCOME TAX EXPENSE	557	490
INCOME TAX EXPENSE	218	180
NET INCOME	$ 339	$ 310

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
NET INCOME	$ 388	$ 310
OTHER COMPREHENSIVE LOSS, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	(1)	0
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	(1)	0
COMPREHENSIVE INCOME	387	310
CECONY
NET INCOME	339	310
OTHER COMPREHENSIVE LOSS, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	0	0
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	0	0
COMPREHENSIVE INCOME	$ 339	$ 310

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES
Net income	$ 388	$ 310
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	329	297
Deferred income taxes	256	174
Rate case amortization and accruals	(31)	(63)
Common equity component of allowance for funds used during construction	(2)	(2)
Net derivative (gains)/losses	(5)	64
Other non-cash items, net	(5)	35
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(66)	(30)
Materials and supplies, including fuel oil and gas in storage	26	8
Other receivables and other current assets	30	(40)
Income taxes receivable	26	151
Prepayments	(394)	(374)
Accounts payable	(78)	(84)
Pensions and retiree benefits obligations, net	105	139
Pensions and retiree benefits contributions	(129)	(153)
Accrued taxes	(26)	(11)
Accrued interest	54	54
Superfund and environmental remediation costs, net	1	55
Distributions from equity investments	35	24
System benefit charge	65	45
Deferred charges, noncurrent assets and other regulatory assets	(53)	(149)
Deferred credits and other regulatory liabilities	(9)	110
Other current and noncurrent liabilities	(69)	(36)
NET CASH FLOWS FROM OPERATING ACTIVITIES	448	524
INVESTING ACTIVITIES
Utility construction expenditures	(714)	(603)
Cost of removal less salvage	(63)	(44)
Non-utility construction expenditures	(113)	(210)
Proceeds from sale of assets	23	0
Restricted cash	19	(1)
Other investing activities	16	(13)
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(837)	(1,118)
FINANCING ACTIVITIES
Net payment of short-term debt	(218)	(330)
Issuance of long-term debt	497	218
Retirement of long-term debt	(408)	(1)
Debt issuance costs	(4)	(3)
Common stock dividends	(199)	(185)
Issuance of common shares for stock plans	12	15
Distribution to noncontrolling interest	0	(1)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(320)	(287)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(709)	(881)
BALANCE AT BEGINNING OF PERIOD	776	944
BALANCE AT END OF PERIOD	67	63
LESS: CHANGE IN CASH BALANCES HELD FOR SALE	0	2
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	67	61
Cash paid/(received) during the period for:
Interest	123	109
Income taxes	(39)	(143)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	282	263
Issuance of common shares for dividend reinvestment	12	12
Electric and Gas Transmission Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	(5)	(22)
Renewable Electric Production Projects
INVESTING ACTIVITIES
Investments in/acquisitions of projects	0	(225)
CECONY
OPERATING ACTIVITIES
Net income	339	310
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	294	272
Deferred income taxes	234	236
Rate case amortization and accruals	(36)	(67)
Common equity component of allowance for funds used during construction	(2)	(2)
Other non-cash items, net	(13)	16
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(54)	(30)
Materials and supplies, including fuel oil and gas in storage	20	18
Other receivables and other current assets	33	13
Accounts receivable from affiliated companies	15	71
Prepayments	(373)	(324)
Accounts payable	(41)	(106)
Pensions and retiree benefits obligations, net	93	132
Pensions and retiree benefits contributions	(128)	(153)
Accrued taxes	(18)	(10)
Accrued interest	56	41
Superfund and environmental remediation costs, net	1	55
System benefit charge	59	41
Accrued taxes to affiliated companies	(21)	(2)
Deferred charges, noncurrent assets and other regulatory assets	(51)	(148)
Deferred credits and other regulatory liabilities	29	111
Other current and noncurrent liabilities	(56)	(16)
NET CASH FLOWS FROM OPERATING ACTIVITIES	380	458
INVESTING ACTIVITIES
Utility construction expenditures	(672)	(565)
Cost of removal less salvage	(61)	(43)
Restricted cash	0	2
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(733)	(606)
FINANCING ACTIVITIES
Net payment of short-term debt	(155)	(513)
Debt issuance costs	0	(1)
Capital contribution by parent	22	23
Dividend to parent	(199)	(186)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(332)	(677)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(685)	(825)
BALANCE AT BEGINNING OF PERIOD	702	843
BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE	17	18
Cash paid/(received) during the period for:
Interest	91	100
Income taxes	(22)	(143)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	$ 217	$ 210

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and temporary cash investments	$ 67	$ 776
Accounts receivable - customers, less allowance for uncollectible accounts	1,175	1,106
Other receivables, less allowance for uncollectible accounts	204	195
Income taxes receivable	53	79
Accrued unbilled revenue	400	447
Fuel oil, gas in storage, materials and supplies, at average cost	313	339
Prepayments	553	159
Regulatory assets	95	100
Restricted cash	35	54
Other current assets	122	151
TOTAL CURRENT ASSETS	3,017	3,406
INVESTMENTS	1,914	1,921
UTILITY PLANT, AT ORIGINAL COST
General	2,717	2,719
TOTAL	40,905	40,411
Less: Accumulated depreciation	8,633	8,541
Net	32,272	31,870
Construction work in progress	1,169	1,175
NET UTILITY PLANT	33,441	33,045
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	1,535	1,482
Construction work in progress	687	689
NET PLANT	35,663	35,216
OTHER NONCURRENT ASSETS
Goodwill	428	428
Intangible assets, less accumulated amortization of $8 and $6 in 2017 and 2016, respectively	122	124
Regulatory assets	7,074	7,024
Other deferred charges and noncurrent assets	147	136
TOTAL OTHER NONCURRENT ASSETS	7,771	7,712
TOTAL ASSETS	48,365	48,255
CURRENT LIABILITIES
Long-term debt due within one year	33	39
Notes payable	836	1,054
Accounts payable	963	1,147
Customer deposits	345	352
Accrued taxes	38	64
Accrued interest	204	150
Accrued wages	102	101
Fair value of derivative liabilities	76	77
Regulatory liabilities	129	128
System benefit charge	499	434
Other current liabilities	216	297
TOTAL CURRENT LIABILITIES	3,441	3,843
NONCURRENT LIABILITIES
Provision for injuries and damages	173	160
Pensions and retiree benefits	1,836	1,847
Superfund and other environmental costs	746	753
Asset retirement obligations	249	246
Fair value of derivative liabilities	66	40
Deferred income taxes and unamortized investment tax credits	10,443	10,205
Regulatory liabilities	1,854	1,905
Other deferred credits and noncurrent liabilities	222	215
TOTAL NONCURRENT LIABILITIES	15,589	15,371
LONG-TERM DEBT	14,829	14,735
EQUITY
Common shareholders’ equity	14,498	14,298
Noncontrolling interest	8	8
TOTAL EQUITY (See Statement of Equity)	14,506	14,306
TOTAL LIABILITIES AND EQUITY	48,365	48,255
CECONY
CURRENT ASSETS
Cash and temporary cash investments	17	702
Accounts receivable - customers, less allowance for uncollectible accounts	1,089	1,032
Other receivables, less allowance for uncollectible accounts	103	81
Accrued unbilled revenue	363	399
Accounts receivable from affiliated companies	94	109
Fuel oil, gas in storage, materials and supplies, at average cost	250	270
Prepayments	473	100
Regulatory assets	85	90
Restricted cash	2	2
Other current assets	60	95
TOTAL CURRENT ASSETS	2,536	2,880
INVESTMENTS	336	315
UTILITY PLANT, AT ORIGINAL COST
General	2,480	2,490
TOTAL	38,311	37,847
Less: Accumulated depreciation	7,925	7,836
Net	30,386	30,011
Construction work in progress	1,102	1,104
NET UTILITY PLANT	31,488	31,115
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	4	4
NET PLANT	31,492	31,119
OTHER NONCURRENT ASSETS
Regulatory assets	6,520	6,473
Other deferred charges and noncurrent assets	66	69
TOTAL OTHER NONCURRENT ASSETS	6,586	6,542
TOTAL ASSETS	40,950	40,856
CURRENT LIABILITIES
Notes payable	445	600
Accounts payable	757	876
Accounts payable to affiliated companies	10	10
Customer deposits	334	336
Accrued taxes	32	50
Accrued taxes to affiliated companies	98	119
Accrued interest	167	111
Accrued wages	92	91
Fair value of derivative liabilities	63	66
Regulatory liabilities	96	90
System benefit charge	457	398
Other current liabilities	170	242
TOTAL CURRENT LIABILITIES	2,721	2,989
NONCURRENT LIABILITIES
Provision for injuries and damages	166	154
Pensions and retiree benefits	1,503	1,544
Superfund and other environmental costs	649	655
Asset retirement obligations	229	227
Fair value of derivative liabilities	60	33
Deferred income taxes and unamortized investment tax credits	9,703	9,450
Regulatory liabilities	1,654	1,712
Other deferred credits and noncurrent liabilities	199	190
TOTAL NONCURRENT LIABILITIES	14,163	13,965
LONG-TERM DEBT	12,075	12,073
EQUITY
Common shareholders’ equity	11,991	11,829
TOTAL LIABILITIES AND EQUITY	40,950	40,856
Electric
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	28,024	27,747
Electric | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	26,384	26,122
Gas
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	7,718	7,524
Gas | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	7,001	6,814
Steam
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,446	2,421
Steam | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	$ 2,446	$ 2,421

Consolidated Balance Sheet (Un6

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Accounts receivable - customers, allowance for uncollectible accounts	$ 66	$ 69
Other receivables, allowance for uncollectible accounts	9	14
Non-utility property, accumulated depreciation	155	140
Intangible assets, accumulated amortization	8	6
CECONY
Accounts receivable - customers, allowance for uncollectible accounts	62	65
Other receivables, allowance for uncollectible accounts	7	13
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, 2015	$ 13,061		$ 32		$ 5,030		$ 9,123			$ (1,038)	$ (61)		$ (34)	$ (9)	$ 9
Beginning Balance at Dec. 31, 2015		$ 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	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 (loss)	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)	(9)	8
Ending Balance (in shares) at Mar. 31, 2016			294,000,000	235,000,000						23,000,000
Beginning Balance at Dec. 31, 2016	14,306		$ 33		5,854		9,559			$ (1,038)	(83)		(27)	(7)	8
Beginning Balance at Dec. 31, 2016	14,298	11,829		$ 589		4,347		7,923	(962)			(61)		(7)
Beginning Balance (in shares) at Dec. 31, 2016			305,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	388	339					388	339
Common stock dividends	(211)	(199)					(211)	(199)
Issuance of common shares for stock plans	24				24
Capital contribution by parent		22				22
Other comprehensive income (loss)	(1)	0											(1)	0
Ending Balance at Mar. 31, 2017	14,498	$ 11,991		$ 589		$ 4,369		$ 8,063	$ (962)			$ (61)		(7)
Ending Balance at Mar. 31, 2017	$ 14,506		$ 33		$ 5,878		$ 9,736			$ (1,038)	$ (83)		$ (28)	$ (7)	$ 8
Ending Balance (in shares) at Mar. 31, 2017			305,000,000	235,000,000						23,000,000

General

General	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
General	General These combined notes accompany and form an integral part of the separate consolidated financial statements of each of the two separate registrants: Consolidated Edison, Inc. and its subsidiaries (Con Edison) and Consolidated Edison Company of New York, Inc. and its subsidiaries (CECONY). CECONY is a subsidiary of Con Edison and as such its financial condition and results of operations and cash flows, which are presented separately in the CECONY consolidated financial statements, are also consolidated, along with those of Orange and Rockland Utilities, Inc. (O&R), Con Edison Clean Energy Businesses, Inc. (together with its subsidiaries, the Clean Energy Businesses) and Con Edison Transmission, Inc. (together with its subsidiaries, Con Edison Transmission) in Con Edison’s consolidated financial statements. The term “Utilities” is used in these notes to refer to CECONY and O&R. As used in these notes, the term “Companies” refers to Con Edison and CECONY and, except as otherwise noted, the information in these combined notes relates to each of the Companies. However, CECONY makes no representation as to information relating to Con Edison or the subsidiaries of Con Edison other than itself. 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, 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 Clean Energy Businesses, Inc. has three subsidiaries: Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company that provides energy-related products and services to retail customers. Con Edison Transmission, Inc. invests in electric transmission facilities through its subsidiary, Consolidated Edison Transmission, LLC (CET Electric), and invests in gas pipeline and storage facilities through its subsidiary Con Edison Gas Pipeline and Storage, LLC (CET Gas).

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Earnings Per Common Share Con Edison presents basic and diluted earnings per share on the face of its consolidated income statement. Basic earnings per share (EPS) are calculated by dividing earnings available to common shareholders (“Net income” on Con Edison’s consolidated income statement) by the weighted average number of Con Edison common shares outstanding during the period. In the calculation of diluted EPS, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for Con Edison consist of restricted stock units, deferred stock units and stock options for which the average market price of the common shares for the period was greater than the exercise price. For the three months ended March 31, 2017 and 2016 , basic and diluted EPS for Con Edison are calculated as follows: For the Three Months Ended March 31, (Millions of Dollars, except per share amounts/Shares in Millions) 2017 2016 Net income $388 $310 Weighted average common shares outstanding – basic 305.1 293.7 Add: Incremental shares attributable to effect of potentially dilutive securities 1.2 1.1 Adjusted weighted average common shares outstanding – diluted 306.3 294.8 Net Income per common share – basic $1.27 $1.05 Net Income per common share – diluted $1.27 $1.05 The computation of diluted EPS for the three months ended March 31, 2017 and 2016 excludes immaterial amounts of performance share awards that were not included because of their anti-dilutive effect. Changes in Accumulated Other Comprehensive Income/(Loss) by Component For the three months ended March 31, 2017 and 2016 , changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Beginning balance, accumulated OCI, net of taxes (a) $(27) $(34) $(7) $(9) OCI before reclassifications, net of tax of $1 for Con Edison in 2017 and 2016 (2) (1) — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2017 and 2016 (a)(b) 1 1 — — Current period OCI, net of taxes (1) — — — Ending balance, accumulated OCI, net of taxes $(28) $(34) $(7) $(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	3 Months Ended
	Mar. 31, 2017
Regulated Operations [Abstract]
Regulatory Matters	Regulatory Matters Rate Plans Rockland Electric Company (RECO) In February 2017, the New Jersey Board of Public Utilities (NJBPU) approved a stipulation of settlement for a RECO electric rate plan commencing March 2017. The following table contains a summary of the electric rate plan. RECO Effective period March 2017 (a) Base rate changes Yr. 1. - $1.7 million Amortization to income of net regulatory (assets) and liabilities $0.2 million over three years and continuation of $(25.6) million of deferred storm costs over four years expiring July 31, 2018 (b) Recoverable energy costs Current rate recovery of purchased power costs. Cost reconciliations None Average rate base Yr. 1 - $178.7 million Weighted average cost of capital (after-tax) 7.47 percent Authorized return on common equity 9.6 percent Cost of long-term debt 5.37 percent Common equity ratio 49.7 percent (a) Effective until a new NJBPU-approved rate plan goes into effect. (b) In January 2016, the NJBPU approved RECO’s plan for a 3 -year, $15.7 million electric system storm hardening capital program, the costs of which RECO, beginning in 2017, is collecting through a customer surcharge. In January 2017, RECO filed a request with FERC for an increase to its annual transmission revenue requirement from $11.8 million to $19.7 million . The filing reflects a return on common equity of 10.7 percent and a common equity ratio of 48 percent . Regulatory Assets and Liabilities Regulatory assets and liabilities at March 31, 2017 and December 31, 2016 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Regulatory assets Unrecognized pension and other postretirement costs $2,911 $2,874 $2,748 $2,730 Future income tax 2,434 2,439 2,321 2,325 Environmental remediation costs 808 823 697 711 Revenue taxes 307 295 291 280 Deferred derivative losses 68 48 62 42 Deferred storm costs 53 56 3 3 Municipal infrastructure support cost 49 44 49 44 Indian Point Energy Center 48 50 48 50 Pension and other postretirement benefits deferrals 48 38 19 7 Surcharge for New York State assessment 45 28 42 26 Unamortized loss on reacquired debt 42 43 40 41 O&R property tax reconciliation 35 37 — — Recoverable energy costs 29 42 26 38 Brooklyn Queens demand management program 28 29 28 29 Preferred stock redemption 25 25 25 25 Net electric deferrals 20 24 20 24 Workers’ compensation 14 13 14 13 O&R transition bond charges 13 15 — — Other 97 101 87 85 Regulatory assets – noncurrent 7,074 7,024 6,520 6,473 Deferred derivative losses 91 91 85 86 Recoverable energy costs 4 9 — 4 Regulatory assets – current 95 100 85 90 Total Regulatory Assets $7,169 $7,124 $6,605 $6,563 Regulatory liabilities Allowance for cost of removal less salvage $772 $755 $649 $641 Pension and other postretirement benefit deferrals 197 193 167 162 Property tax reconciliation 162 178 162 178 Net unbilled revenue deferrals 104 145 104 145 Unrecognized other postretirement costs 91 60 91 60 Settlement of prudence proceeding 87 95 87 95 Carrying charges on repair allowance and bonus depreciation 62 68 61 67 New York State income tax rate change 56 61 55 60 Variable-rate tax-exempt debt – cost rate reconciliation 50 55 44 48 Base rate change deferrals 36 40 36 40 Settlement of gas proceedings 27 27 27 27 Earnings sharing - electric, gas and steam 20 39 10 28 Net utility plant reconciliations 15 16 13 15 Other 175 173 148 146 Regulatory liabilities – noncurrent 1,854 1,905 1,654 1,712 Refundable energy costs 60 29 36 5 Revenue decoupling mechanism 41 71 38 61 Deferred derivative gains 28 28 22 24 Regulatory liabilities – current 129 128 96 90 Total Regulatory Liabilities $1,983 $2,033 $1,750 $1,802

Capitalization

Capitalization	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Capitalization	Capitalization In March 2017, Con Edison issued $400 million aggregate principal amount of 2.00 percent debentures, due 2020, and prepaid the $400 million variable rate term loan that was to mature in 2018. Also, in March 2017, a Con Edison Development subsidiary issued $97 million aggregate principal amount of 4.45 percent senior notes, due 2042, secured by the company’s Upton County Solar project. The carrying amounts and fair values of long-term debt at March 31, 2017 and December 31, 2016 were: (Millions of Dollars) 2017 2016 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $14,862 $16,206 $14,774 $16,093 CECONY $12,075 $13,288 $12,073 $13,268 Fair values of long-term debt have been estimated primarily using available market information. For Con Edison, $15,570 million and $636 million of the fair value of long-term debt at March 31, 2017 are classified as Level 2 and Level 3, respectively. For CECONY, $12,652 million and $636 million of the fair value of long-term debt at March 31, 2017 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	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Short-Term Borrowing	Short-Term Borrowing At March 31, 2017 , Con Edison had $836 million of commercial paper outstanding of which $445 million was outstanding under CECONY’s program. The weighted average interest rate at March 31, 2017 was 1.1 percent for both Con Edison and CECONY. At December 31, 2016 , Con Edison had $1,054 million of commercial paper outstanding of which $600 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2016 was 1.0 percent for both Con Edison and CECONY. At March 31, 2017 and December 31, 2016 , no loans were outstanding under the credit agreement (Credit Agreement). An immaterial amount and $2 million (including $2 million for CECONY) of letters of credit were outstanding under the Credit Agreement as of March 31, 2017 and December 31, 2016 , respectively.

Pension Benefits

Pension Benefits	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Pension Benefits	Pension Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for the three months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Service cost – including administrative expenses $66 $69 $61 $65 Interest cost on projected benefit obligation 148 149 139 140 Expected return on plan assets (243) (237) (229) (225) Recognition of net actuarial loss 149 149 141 141 Recognition of prior service costs (4) 1 (5) — TOTAL PERIODIC BENEFIT COST $116 $131 $107 $121 Cost capitalized (43) (52) (41) (49) Reconciliation to rate level (11) 12 (12) 13 Cost charged to operating expenses $62 $91 $54 $85 Expected Contributions Based on estimates as of March 31, 2017 , the Companies expect to make contributions to the pension plans during 2017 of $450 million (of which $412 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 three months of 2017 , the Companies contributed $129 million to the pension plans, nearly all of which was contributed by CECONY.

Other Postretirement Benefits

Other Postretirement Benefits	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Other Postretirement Benefits	Other Postretirement Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic other postretirement benefit costs for the three months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Service cost $5 $4 $3 $3 Interest cost on accumulated other postretirement benefit obligation 11 12 10 10 Expected return on plan assets (17) (19) (15) (17) Recognition of net actuarial loss 1 1 (1) 1 Recognition of prior service cost (4) (5) (3) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(4) $(7) $(6) $(7) Cost capitalized 2 2 2 2 Reconciliation to rate level (1) 7 — 7 Cost charged to operating expenses $(3) $2 $(4) $2 Expected Contributions Based on estimates as of March 31, 2017 , Con Edison expects to make a contribution of $16 million , of which $8 million is to be contributed by CECONY, to the other postretirement benefit plans in 2017 . The Companies' policy is to fund the total periodic benefit cost of the plans to the extent tax deductible.

Environmental Matters

Environmental Matters	3 Months Ended
	Mar. 31, 2017
Environmental Remediation Obligations [Abstract]
Environmental Matters	Environmental Matters Superfund Sites Hazardous substances, such as asbestos, polychlorinated biphenyls (PCBs) and coal tar, have been used or generated in the course of operations of the Utilities and their predecessors and are present at sites and in facilities and equipment they currently or previously owned, including sites at which gas was manufactured or stored. The Federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 and similar state statutes (Superfund) impose joint and several liability, regardless of fault, upon generators of hazardous substances for investigation and remediation costs (which include costs of demolition, removal, disposal, storage, replacement, containment and monitoring) and natural resource damages. Liability under these laws can be material and may be imposed for contamination from past acts, even though such past acts may have been lawful at the time they occurred. The sites at which the Utilities have been asserted to have liability under these laws, including their manufactured gas plant sites and any neighboring areas to which contamination may have migrated, are referred to herein as “Superfund Sites.” For Superfund Sites where there are other potentially responsible parties and the Utilities are not managing the site investigation and remediation, the accrued liability represents an estimate of the amount the Utilities will need to pay to investigate and, where determinable, discharge their related obligations. For Superfund Sites (including the manufactured gas plant sites) for which one of the Utilities is managing the investigation and remediation, the accrued liability represents an estimate of the company’s share of the undiscounted cost to investigate the sites and, for sites that have been investigated in whole or in part, the cost to remediate the sites, if remediation is necessary and if a reasonable estimate of such cost can be made. Remediation costs are estimated in light of the information available, applicable remediation standards and experience with similar sites. The accrued liabilities and regulatory assets related to Superfund Sites at March 31, 2017 and December 31, 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Accrued Liabilities: Manufactured gas plant sites $659 $664 $562 $567 Other Superfund Sites 87 89 87 88 Total $746 $753 $649 $655 Regulatory assets $808 $823 $697 $711 Most of the accrued Superfund Site liability relates to sites that have been investigated, in whole or in part. However, for some of the sites, the extent and associated cost of the required remediation has not yet been determined. As investigations progress and information pertaining to the required remediation becomes available, the Utilities expect that additional liability may be accrued, the amount of which is not presently determinable but may be material. The Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) prudently incurred site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites for the three months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Remediation costs incurred $7 $3 $7 $3 Insurance recoveries received by Con Edison or CECONY were immaterial for the three months ended March 31, 2017 . No insurance recoveries were received by Con Edison or CECONY for the three months ended March 31, 2016 . In 2016, Con Edison and CECONY estimated that for their manufactured gas plant sites (including CECONY’s Astoria site), the aggregate undiscounted potential liability for the investigation and remediation of coal tar and/or other environmental contaminants could range up to $2.8 billion and $2.6 billion , respectively. These estimates were based on the assumption that there is contamination at all sites, including those that have not yet been fully investigated and additional assumptions about the extent of the contamination and the type and extent of the remediation that may be required. Actual experience may be materially different. Asbestos Proceedings Suits have been brought in New York State and federal courts against the Utilities and many other defendants, wherein a large number of plaintiffs sought large amounts of compensatory and punitive damages for deaths and injuries allegedly caused by exposure to asbestos at various premises of the Utilities. The suits that have been resolved, which are many, have been resolved without any payment by the Utilities, or for amounts that were not, in the aggregate, material to them. The amounts specified in all the remaining thousands of suits total billions of dollars; however, the Utilities believe that these amounts are greatly exaggerated, based on the disposition of previous claims. At March 31, 2017 , Con Edison and CECONY have accrued their estimated aggregate undiscounted potential liabilities for these suits and additional suits that may be brought over the next 15 years as shown in the following table. These estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Courts have begun, and unless otherwise determined on appeal may continue, to apply different standards for determining liability in asbestos suits than the standard that applied historically. As a result, the Companies currently believe that there is a reasonable possibility of an exposure to loss in excess of the liability accrued for the suits. The Companies are unable to estimate the amount or range of such loss. In addition, certain current and former employees have claimed or are claiming workers’ compensation benefits based on alleged disability from exposure to asbestos. CECONY is permitted to defer as regulatory assets (for subsequent recovery through rates) costs incurred for its asbestos lawsuits and workers’ compensation claims. The accrued liability for asbestos suits and workers’ compensation proceedings (including those related to asbestos exposure) and the amounts deferred as regulatory assets for the Companies at March 31, 2017 and December 31, 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $88 $88 $84 $83 Regulatory assets – workers’ compensation $14 $13 $14 $13

Other Material Contingencies

Other Material Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
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 fifty-five 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 March 31, 2017 , the company has accrued its estimated liability for the suits of $25 million and an insurance receivable of $25 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. In June 2015, the NTSB issued a final report concerning the incident, its probable cause and safety recommendations. The NTSB determined that the probable cause of the incident was (1) the failure of a defective fusion joint at a service tee (which joined a plastic service line to a plastic distribution main) installed by the company that allowed gas to leak from the distribution main and migrate into a building where it ignited and (2) a breach in a City sewer line that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the distribution main, which caused it to sag and overstressed the defective fusion joint. The NTSB also made safety recommendations, including recommendations to the company that addressed its procedures for the preparation and examination of plastic fusions, training of its staff on conditions for notifications to the City’s Fire Department and extension of its gas main isolation valve installation program. In February 2017, the NYSPSC approved a settlement agreement with the company related to the NYSPSC's investigations of the incident and the practices of qualifying persons to perform plastic fusions. Pursuant to the agreement, the company will not recover from customers $126 million of costs it incurred for gas emergency response activities in 2014, 2015 and 2016 in excess of the amounts reflected in its gas rate plan and will provide $27 million of future benefits to customers (for which it has accrued a regulatory liability, see Note B). Approximately eighty suits are pending against the company seeking generally unspecified damages and, in some cases, punitive damages, for wrongful death, personal injury, property damage and business interruption. The company has notified its insurers of the incident and believes that the policies in force at the time of the incident will cover the company’s costs, in excess of a required retention (the amount of which is not material), to satisfy any liability it may have for damages in connection with the incident. The company is unable to estimate the amount or range of its possible loss for damages related to the incident. At March 31, 2017 , the company had not accrued a liability for damages related to the incident. Other Contingencies See “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 $2,193 million and $2,370 million at March 31, 2017 and December 31, 2016 , respectively. A summary, by type and term, of Con Edison’s total guarantees at March 31, 2017 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $460 $587 $— $1,047 Energy transactions 512 35 185 732 Renewable electric production projects 267 — 19 286 Other 128 — — 128 Total $1,367 $622 $204 $2,193 Con Edison Transmission — Con Edison has guaranteed payment by CET Electric of the contributions CET Electric agreed to make to New York Transco LLC (NY Transco). CET Electric acquired a 45.7 percent interest in NY Transco when it was formed in 2014. In May 2016, the transmission owners transferred certain projects to NY Transco, 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. Energy Transactions — Con Edison guarantees payments on behalf of the Clean Energy Businesses in order to facilitate physical and financial transactions in electricity, gas, pipeline capacity, transportation, oil, renewable energy credits and energy services. To the extent that liabilities exist under the contracts subject to these guarantees, such liabilities are included in Con Edison’s consolidated balance sheet. Guarantee amounts shown above include $21 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. 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 operation of solar energy facilities and energy service projects of Con Edison Development and Con Edison Solutions, respectively. Other guarantees also includes Con Edison's guarantee (subject to a $53 million maximum amount) of certain obligations of Con Edison Solutions under the agreement pursuant to which it sold its retail electric supply business. 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	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax	Income Tax Con Edison’s income tax expense increased to $227 million for the three months ended March 31, 2017 from $164 million for the three months ended March 31, 2016 . Con Edison's effective tax rate for the three months ended March 31, 2017 and 2016 was 37 percent and 35 percent , respectively. The increase in Con Edison's effective tax rate is primarily due to a decrease in tax benefits for plant-related flow through items and research and development tax credits, offset in part by lower state income taxes. CECONY’s income tax expense increased to $218 million for the three months ended March 31, 2017 from $180 million for the three months ended March 31, 2016 . CECONY's effective tax rate for the three months ended March 31, 2017 and 2016 was 39 percent and 37 percent , respectively. The increase in CECONY's effective tax rate is primarily due to a decrease in tax benefits for plant-related flow through items and research and development tax credits, offset in part by lower state income taxes. Con Edison anticipates a federal consolidated net operating loss for 2017, primarily due to bonus depreciation. Con Edison expects to carryback a portion of its 2017 net operating loss to recover $22 million of income tax and the remaining 2017 net operating loss, as well as general business tax credits generated in 2017, 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 March 31, 2017 , the estimated liability for uncertain tax positions for Con Edison was $40 million ( $21 million for CECONY). Con Edison reasonably expects to resolve approximately $33 million ( $23 million , net of federal taxes) of its uncertain tax positions within the next twelve months, including $19 million ( $13 million , net of federal taxes), which, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $17 million ( $12 million , net of federal taxes), including $2 million , which, 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 $23 million ( $16 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 months ended March 31, 2017 , the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At March 31, 2017 and December 31, 2016 , the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.

Financial Information by Busine

Financial Information by Business Segment	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Financial Information by Business Segment	Financial Information by Business Segment Con Edison’s principal business segments are CECONY’s regulated utility activities, O&R’s regulated utility activities, the Clean Energy Businesses and Con Edison Transmission. CECONY’s principal business segments are its regulated electric, gas and steam utility activities. The financial data for the business segments are as follows: For the Three Months Ended March 31, Operating revenues Inter-segment revenues Depreciation and amortization Operating income/(loss) (Millions of Dollars) 2017 2016 2017 2016 2017 2016 2017 2016 CECONY Electric $1,793 $1,773 $5 $4 $229 $213 $292 $273 Gas 765 601 1 1 44 38 292 253 Steam 298 258 18 22 21 21 121 114 Consolidation adjustments — — (24) (27) — — — — Total CECONY $2,856 $2,632 $— $— $294 $272 $705 $640 O&R Electric $141 $140 $— $— $12 $12 $14 $18 Gas 97 75 — — 5 5 39 35 Total O&R $238 $215 $— $— $17 $17 $53 $53 Clean Energy Businesses $136 $310 $— $6 $17 $9 $15 $(51) Con Edison Transmission — — — — — — (3) — Other (a) (2) (1) — (6) 1 (1) 1 — Total Con Edison $3,228 $3,156 $— $— $329 $297 $771 $642 (a) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
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 March 31, 2017 and December 31, 2016 were: (Millions of Dollars) 2017 2016 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 $71 $(39) $32 (b) $81 $(64) $17 (b) Noncurrent 19 (19) — 49 (43) 6 Total fair value of derivative assets $90 $(58) $32 $130 $(107) $23 Fair value of derivative liabilities Current $(117) $41 $(76) $(138) $61 $(77) Noncurrent (85) 19 (66) (91) 52 (39) (c) Total fair value of derivative liabilities $(202) $60 $(142) $(229) $113 $(116) Net fair value derivative assets/(liabilities) $(112) $2 $(110) (b) $(99) $6 $(93) (b) (c) CECONY Fair value of derivative assets Current $41 $(23) $18 (b) $52 $(45) $7 (b) Noncurrent 13 (13) — 41 (35) 6 Total fair value of derivative assets $54 $(36) $18 $93 $(80) $13 Fair value of derivative liabilities Current $(91) $28 $(63) $(111) $45 $(66) Noncurrent (73) 13 (60) (77) 44 (33) Total fair value of derivative liabilities $(164) $41 $(123) $(188) $89 $(99) Net fair value derivative assets/(liabilities) $(110) $5 $(105) (b) $(95) $9 $(86) (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 March 31, 2017 and December 31, 2016 , margin deposits for Con Edison ( $9 million and $7 million , respectively) and CECONY ( $9 million and $7 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include $(1) million for interest rate swap. 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. The Clean Energy Businesses record realized and unrealized gains and losses on their derivative contracts in purchased power, gas purchased for resale and non-utility revenue in the reporting period in which they occur. Management believes that these derivative instruments represent economic hedges that mitigate exposure to fluctuations in commodity prices. The following table presents the realized and unrealized gains or losses on commodity derivatives that have been deferred or recognized in earnings for the three months ended March 31, 2017 and 2016 : For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2017 2016 2017 2016 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $— $(4) $(2) $(4) Noncurrent Deferred derivative gains (3) — (3) (1) Total deferred gains/(losses) $(3) $(4) $(5) $(5) Current Deferred derivative losses $— $(30) $1 $(28) Current Recoverable energy costs (45) (73) (40) (66) Noncurrent Deferred derivative losses (20) (56) (20) (51) Total deferred gains/(losses) $(65) $(159) $(59) $(145) Net deferred gains/(losses) $(68) $(163) $(64) $(150) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $— $(114) (b) $— $— Gas purchased for resale (63) (10) — — Non-utility revenue 14 (a) 11 (b) — — Total pre-tax gain/(loss) recognized in income $(49) $(113) $— $— (a) For the three months ended March 31, 2017 , Con Edison recorded unrealized pre-tax gains in non-utility operating revenue ( $3 million ). (b) For the three months ended March 31, 2016 , Con Edison recorded unrealized pre-tax losses in non-utility operating revenue ( $1 million loss) and purchased power expense ( $62 million loss). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at March 31, 2017 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 19,410,040 11,631 69,548,736 2,688,000 CECONY 17,605,375 6,000 62,210,000 2,688,000 (a) Volumes are reported net of long and short positions, except natural gas collars where the volumes of long positions are reported. (b) Excludes electric congestion and gas basis swap contracts, which are associated with electric and gas contracts and hedged volumes. The Companies are exposed to credit risk related to transactions entered into primarily for the various energy supply and hedging activities by the Utilities and the Clean Energy Businesses. Credit risk relates to the loss that may result from a counterparty’s nonperformance. The Companies use credit policies to manage this risk, including an established credit approval process, monitoring of counterparty limits, netting provisions within agreements, collateral or prepayment arrangements, credit insurance and credit default swaps. The Companies measure credit risk exposure as the replacement cost for open energy commodity and derivative positions plus amounts owed from counterparties for settled transactions. The replacement cost of open positions represents unrealized gains, net of any unrealized losses where the Companies have a legally enforceable right to offset. At March 31, 2017 , Con Edison and CECONY had $63 million and $10 million of credit exposure in connection with energy supply and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $20 million with investment-grade counterparties, $20 million with commodity exchange brokers, $16 million with non-investment grade/non-rated counterparties, and $7 million with independent system operators. CECONY’s net credit exposure consisted of $9 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 March 31, 2017 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $116 $106 Collateral posted 37 35 Additional collateral (b) (downgrade one level from current ratings) 17 16 Additional collateral (b) (downgrade to below investment grade from current ratings) 98 (c) 83 (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 Clean Energy Businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $12 million at March 31, 2017 . 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 liability 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 March 31, 2017 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $12 million . Interest Rate Swap In December 2016, the Clean Energy Businesses acquired Coram Wind project which holds an interest rate swap that terminates in June 2024, pursuant to which it pays a fixed-rate of 2.0855 percent and receives a LIBOR-based variable rate. The fair value of this interest rate swap was an immaterial amount as of March 31, 2017 and a liability of $1 million as of December 31, 2016 on Con Edison’s consolidated balance sheet.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The accounting rules for fair value measurements and disclosures define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable firm inputs. The Companies often make certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. The Companies use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting rules for fair value measurements and disclosures established a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The rules require that assets and liabilities be classified in their entirety based on the level of input that is significant to the fair value measurement. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and their placement within the fair value hierarchy. The Companies classify fair value balances based on the fair value hierarchy defined by the accounting rules for fair value measurements and disclosures as follows: • Level 1 – Consists of assets or liabilities whose value is based on unadjusted quoted prices in active markets at the measurement date. An active market is one in which transactions for assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes contracts traded on active exchange markets valued using unadjusted prices quoted directly from the exchange. • Level 2 – Consists of assets or liabilities valued using industry standard models and based on prices, other than quoted prices within Level 1, that are either directly or indirectly observable as of the measurement date. The industry standard models consider observable assumptions including time value, volatility factors and current market and contractual prices for the underlying commodities, in addition to other economic measures. This category includes contracts traded on active exchanges or in over-the-counter markets priced with industry standard models. • Level 3 – Consists of assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost benefit constraints. This category includes contracts priced using models that are internally developed and contracts placed in illiquid markets. It also includes contracts that expire after the period of time for which quoted prices are available and internal models are used to determine a significant portion of the value. Assets and liabilities measured at fair value on a recurring basis as of March 31, 2017 and December 31, 2016 are summarized below. 2017 2016 (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) $12 $20 $6 $3 $41 $14 $33 $7 $(24) $30 Other (a)(b)(d) 240 114 — — 354 222 111 — — 333 Total assets $252 $134 $6 $3 $395 $236 $144 $7 $(24) $363 Derivative liabilities: Commodity (a)(b)(c) $5 $142 $3 $(8) $142 $4 $144 $6 $(38) $116 Interest Rate Swap (a)(b)(c) — — — — — — 1 — — 1 Total liabilities $5 $142 $3 $(8) $142 $4 $145 $6 $(38) $117 CECONY Derivative assets: Commodity (a)(b)(c) $5 $7 $1 $14 $27 $10 $19 $1 $(10) $20 Other (a)(b)(d) 217 109 — — 326 200 106 — — 306 Total assets $222 $116 $1 $14 $353 $210 $125 $1 $(10) $326 Derivative liabilities: Commodity (a)(b)(c) $— $122 $— $1 $123 $1 $124 $— $(26) $99 (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 three months ended March 31, 2017 and for the year ended December 31, 2016 . (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 March 31, 2017 and December 31, 2016 , 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. The employees in the Companies’ risk management group develop and maintain the Companies’ valuation policies and procedures for, and verify pricing and fair value valuation of, commodity derivatives. Under the Companies’ policies and procedures, multiple independent sources of information are obtained for forward price curves used to value commodity derivatives. Fair value and changes in fair value of commodity derivatives are reported on a monthly basis to the Companies’ risk committees, comprised of officers and employees of the Companies that oversee energy hedging at the Utilities and the Clean Energy Businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at March 31, 2017 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $2 Discounted Cash Flow Forward energy prices (a) $21.75-$81.00 per MWh Discounted Cash Flow Forward capacity prices (a) $2.42-$10.70 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) 50.0% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (75.2)%-58.9% Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.50-$10.26 per MWh Total Con Edison—Commodity $3 CECONY—Commodity Transmission Congestion Contracts $1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 50.0% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (75.2)%-58.9% (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 March 31, 2017 and 2016 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Beginning balance as of January 1, $1 $6 $1 $8 Included in earnings — (7) — (1) Included in regulatory assets and liabilities 2 (3) — (4) Settlements — — — (1) Ending balance as of March 31, $3 $(4) $1 $2 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 Clean 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 ( immaterial and $6 million loss ) on the consolidated income statement for the three months ended March 31, 2017 and 2016 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at March 31, 2017 and 2016 is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( immaterial and $4 million loss ) on the consolidated income statement for the three months ended March 31, 2017 and 2016 , respectively.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
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 has ongoing long-term electricity purchase agreements with the following two potential variable interest entities (VIEs): Cogen Technologies Linden Venture, LP and Brooklyn Navy Yard Cogeneration Partners, LP. In 2016 , requests were made of these 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 March 31, 2017 : 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 $173 Mesquite Solar 1 83 20 2013 Arizona 97 Copper Mountain Solar 2 75 25 2013 Nevada 80 California Solar 55 25 2012 California 59 Broken Bow II 38 25 2014 Nebraska 47 Texas Solar 4 32 25 2014 Texas 46 (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. With the exception of Texas Solar 4, 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. (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. For consolidated investments, such as Texas Solar 4, maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest ( $7 million for Texas Solar 4). Con Edison did not provide any financial or other support during the three months ended March 31, 2017 that was not previously contractually required.

New Financial Accounting Standa

New Financial Accounting Standards	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [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. Amendments were issued subsequently to clarify key areas including principal/agent considerations, performance obligations, licensing, sales taxes, noncash consideration, and contracts. 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, however, the Companies plan to adopt the new standard for reporting periods beginning after December 15, 2017. Under the new standard, companies may use either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a modified retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). The Companies anticipate using the modified retrospective approach. The Companies are currently in the process of evaluating the impact of the new standard on their various revenue streams. The majority of the Companies’ sales are derived from tariffs to provide electric, gas, and steam service to customers. For such tariffs, the Companies expect that the revenue from contracts with the customer under ASU 2014-09 will be equivalent to the electricity, gas, or steam supplied in that period which is consistent with current practice. Consequently, the Companies do not anticipate that the new standard will significantly impact the amount and/or timing of such revenues. The Companies continue to review the potential impacts of other revenue at the Utilities and the Clean Energy Businesses on the Companies' financial position, results of operations and liquidity as well as the additional disclosures required under the new standard. In January 2017, the FASB issued amendments to the guidance for Business Combinations through ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” The amendments in this update clarify the definition of a business and provide guidance on evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. 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 January 2017, the FASB issued amendments to the guidance for the subsequent measurement of goodwill through ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The amendments in this update simplify goodwill impairment testing by eliminating Step 2 of the goodwill impairment test wherein an entity has to compute the implied fair value of goodwill by performing procedures to determine the fair value of its assets and liabilities. Under the new guidance, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value up to the total amount of goodwill allocated to that reporting unit. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In February 2017, the FASB issued amendments to the guidance for other income through ASU 2017-05, “Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets.” The amendments in this update clarify the scope of assets within Subtopic 610-20 and add guidance for partial sales of nonfinancial assets. The amendments are effective upon the adoption of ASU 2014-09, and therefore will be effective for reporting periods beginning after December 15, 2017. The Company is in the process of evaluating the potential impact of the new guidance on the Company’s financial position, results of operations and liquidity. In March 2017, the FASB issued amendments to the guidance for retirement benefits through ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The amendments in this update modify the presentation of net benefit cost, where the service component must be disaggregated from the other components of net benefit cost and be presented in the same line item as current employee compensation costs. The remaining components of the net benefit cost should be presented outside of income from operations. Additionally, the update allows only the service cost component to be eligible for capitalization. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted. 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 2017, the FASB issued amendments to the guidance for debt securities through ASU 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” The amendments in this update shorten the amortization period for certain callable debt securities held at a premium. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity.

New Financial Accounting Stan23

New Financial Accounting Standards (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [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. Amendments were issued subsequently to clarify key areas including principal/agent considerations, performance obligations, licensing, sales taxes, noncash consideration, and contracts. 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, however, the Companies plan to adopt the new standard for reporting periods beginning after December 15, 2017. Under the new standard, companies may use either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a modified retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). The Companies anticipate using the modified retrospective approach. The Companies are currently in the process of evaluating the impact of the new standard on their various revenue streams. The majority of the Companies’ sales are derived from tariffs to provide electric, gas, and steam service to customers. For such tariffs, the Companies expect that the revenue from contracts with the customer under ASU 2014-09 will be equivalent to the electricity, gas, or steam supplied in that period which is consistent with current practice. Consequently, the Companies do not anticipate that the new standard will significantly impact the amount and/or timing of such revenues. The Companies continue to review the potential impacts of other revenue at the Utilities and the Clean Energy Businesses on the Companies' financial position, results of operations and liquidity as well as the additional disclosures required under the new standard. In January 2017, the FASB issued amendments to the guidance for Business Combinations through ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” The amendments in this update clarify the definition of a business and provide guidance on evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. 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 January 2017, the FASB issued amendments to the guidance for the subsequent measurement of goodwill through ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” The amendments in this update simplify goodwill impairment testing by eliminating Step 2 of the goodwill impairment test wherein an entity has to compute the implied fair value of goodwill by performing procedures to determine the fair value of its assets and liabilities. Under the new guidance, an entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value up to the total amount of goodwill allocated to that reporting unit. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In February 2017, the FASB issued amendments to the guidance for other income through ASU 2017-05, “Other Income-Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets.” The amendments in this update clarify the scope of assets within Subtopic 610-20 and add guidance for partial sales of nonfinancial assets. The amendments are effective upon the adoption of ASU 2014-09, and therefore will be effective for reporting periods beginning after December 15, 2017. The Company is in the process of evaluating the potential impact of the new guidance on the Company’s financial position, results of operations and liquidity. In March 2017, the FASB issued amendments to the guidance for retirement benefits through ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The amendments in this update modify the presentation of net benefit cost, where the service component must be disaggregated from the other components of net benefit cost and be presented in the same line item as current employee compensation costs. The remaining components of the net benefit cost should be presented outside of income from operations. Additionally, the update allows only the service cost component to be eligible for capitalization. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted. 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 2017, the FASB issued amendments to the guidance for debt securities through ASU 2017-08, “Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities.” The amendments in this update shorten the amortization period for certain callable debt securities held at a premium. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Basic and Diluted Earnings Per Share	For the three months ended March 31, 2017 and 2016 , basic and diluted EPS for Con Edison are calculated as follows: For the Three Months Ended March 31, (Millions of Dollars, except per share amounts/Shares in Millions) 2017 2016 Net income $388 $310 Weighted average common shares outstanding – basic 305.1 293.7 Add: Incremental shares attributable to effect of potentially dilutive securities 1.2 1.1 Adjusted weighted average common shares outstanding – diluted 306.3 294.8 Net Income per common share – basic $1.27 $1.05 Net Income per common share – diluted $1.27 $1.05
Changes in Accumulated Other Comprehensive Income/(Loss)	For the three months ended March 31, 2017 and 2016 , changes to accumulated other comprehensive income/(loss) (OCI) for Con Edison and CECONY are as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Beginning balance, accumulated OCI, net of taxes (a) $(27) $(34) $(7) $(9) OCI before reclassifications, net of tax of $1 for Con Edison in 2017 and 2016 (2) (1) — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2017 and 2016 (a)(b) 1 1 — — Current period OCI, net of taxes (1) — — — Ending balance, accumulated OCI, net of taxes $(28) $(34) $(7) $(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)	3 Months Ended
	Mar. 31, 2017
Regulated Operations [Abstract]
Summary of Utilities Rate Plans	The following table contains a summary of the electric rate plan. RECO Effective period March 2017 (a) Base rate changes Yr. 1. - $1.7 million Amortization to income of net regulatory (assets) and liabilities $0.2 million over three years and continuation of $(25.6) million of deferred storm costs over four years expiring July 31, 2018 (b) Recoverable energy costs Current rate recovery of purchased power costs. Cost reconciliations None Average rate base Yr. 1 - $178.7 million Weighted average cost of capital (after-tax) 7.47 percent Authorized return on common equity 9.6 percent Cost of long-term debt 5.37 percent Common equity ratio 49.7 percent (a) Effective until a new NJBPU-approved rate plan goes into effect. (b) In January 2016, the NJBPU approved RECO’s plan for a 3 -year, $15.7 million electric system storm hardening capital program, the costs of which RECO, beginning in 2017, is collecting through a customer surcharge.
Schedule of Regulatory Assets	Regulatory assets and liabilities at March 31, 2017 and December 31, 2016 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Regulatory assets Unrecognized pension and other postretirement costs $2,911 $2,874 $2,748 $2,730 Future income tax 2,434 2,439 2,321 2,325 Environmental remediation costs 808 823 697 711 Revenue taxes 307 295 291 280 Deferred derivative losses 68 48 62 42 Deferred storm costs 53 56 3 3 Municipal infrastructure support cost 49 44 49 44 Indian Point Energy Center 48 50 48 50 Pension and other postretirement benefits deferrals 48 38 19 7 Surcharge for New York State assessment 45 28 42 26 Unamortized loss on reacquired debt 42 43 40 41 O&R property tax reconciliation 35 37 — — Recoverable energy costs 29 42 26 38 Brooklyn Queens demand management program 28 29 28 29 Preferred stock redemption 25 25 25 25 Net electric deferrals 20 24 20 24 Workers’ compensation 14 13 14 13 O&R transition bond charges 13 15 — — Other 97 101 87 85 Regulatory assets – noncurrent 7,074 7,024 6,520 6,473 Deferred derivative losses 91 91 85 86 Recoverable energy costs 4 9 — 4 Regulatory assets – current 95 100 85 90 Total Regulatory Assets $7,169 $7,124 $6,605 $6,563 Regulatory liabilities Allowance for cost of removal less salvage $772 $755 $649 $641 Pension and other postretirement benefit deferrals 197 193 167 162 Property tax reconciliation 162 178 162 178 Net unbilled revenue deferrals 104 145 104 145 Unrecognized other postretirement costs 91 60 91 60 Settlement of prudence proceeding 87 95 87 95 Carrying charges on repair allowance and bonus depreciation 62 68 61 67 New York State income tax rate change 56 61 55 60 Variable-rate tax-exempt debt – cost rate reconciliation 50 55 44 48 Base rate change deferrals 36 40 36 40 Settlement of gas proceedings 27 27 27 27 Earnings sharing - electric, gas and steam 20 39 10 28 Net utility plant reconciliations 15 16 13 15 Other 175 173 148 146 Regulatory liabilities – noncurrent 1,854 1,905 1,654 1,712 Refundable energy costs 60 29 36 5 Revenue decoupling mechanism 41 71 38 61 Deferred derivative gains 28 28 22 24 Regulatory liabilities – current 129 128 96 90 Total Regulatory Liabilities $1,983 $2,033 $1,750 $1,802
Schedule of Regulatory Liabilities	Regulatory assets and liabilities at March 31, 2017 and December 31, 2016 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Regulatory assets Unrecognized pension and other postretirement costs $2,911 $2,874 $2,748 $2,730 Future income tax 2,434 2,439 2,321 2,325 Environmental remediation costs 808 823 697 711 Revenue taxes 307 295 291 280 Deferred derivative losses 68 48 62 42 Deferred storm costs 53 56 3 3 Municipal infrastructure support cost 49 44 49 44 Indian Point Energy Center 48 50 48 50 Pension and other postretirement benefits deferrals 48 38 19 7 Surcharge for New York State assessment 45 28 42 26 Unamortized loss on reacquired debt 42 43 40 41 O&R property tax reconciliation 35 37 — — Recoverable energy costs 29 42 26 38 Brooklyn Queens demand management program 28 29 28 29 Preferred stock redemption 25 25 25 25 Net electric deferrals 20 24 20 24 Workers’ compensation 14 13 14 13 O&R transition bond charges 13 15 — — Other 97 101 87 85 Regulatory assets – noncurrent 7,074 7,024 6,520 6,473 Deferred derivative losses 91 91 85 86 Recoverable energy costs 4 9 — 4 Regulatory assets – current 95 100 85 90 Total Regulatory Assets $7,169 $7,124 $6,605 $6,563 Regulatory liabilities Allowance for cost of removal less salvage $772 $755 $649 $641 Pension and other postretirement benefit deferrals 197 193 167 162 Property tax reconciliation 162 178 162 178 Net unbilled revenue deferrals 104 145 104 145 Unrecognized other postretirement costs 91 60 91 60 Settlement of prudence proceeding 87 95 87 95 Carrying charges on repair allowance and bonus depreciation 62 68 61 67 New York State income tax rate change 56 61 55 60 Variable-rate tax-exempt debt – cost rate reconciliation 50 55 44 48 Base rate change deferrals 36 40 36 40 Settlement of gas proceedings 27 27 27 27 Earnings sharing - electric, gas and steam 20 39 10 28 Net utility plant reconciliations 15 16 13 15 Other 175 173 148 146 Regulatory liabilities – noncurrent 1,854 1,905 1,654 1,712 Refundable energy costs 60 29 36 5 Revenue decoupling mechanism 41 71 38 61 Deferred derivative gains 28 28 22 24 Regulatory liabilities – current 129 128 96 90 Total Regulatory Liabilities $1,983 $2,033 $1,750 $1,802

Capitalization (Tables)

Capitalization (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Carrying Amounts and Fair Values of Long-Term Debt	The carrying amounts and fair values of long-term debt at March 31, 2017 and December 31, 2016 were: (Millions of Dollars) 2017 2016 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $14,862 $16,206 $14,774 $16,093 CECONY $12,075 $13,288 $12,073 $13,268

Pension Benefits (Tables)

Pension Benefits (Tables)	3 Months Ended
	Mar. 31, 2017
Pension Benefits
Total Periodic Benefit Costs	The components of the Companies’ total periodic benefit costs for the three months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Service cost – including administrative expenses $66 $69 $61 $65 Interest cost on projected benefit obligation 148 149 139 140 Expected return on plan assets (243) (237) (229) (225) Recognition of net actuarial loss 149 149 141 141 Recognition of prior service costs (4) 1 (5) — TOTAL PERIODIC BENEFIT COST $116 $131 $107 $121 Cost capitalized (43) (52) (41) (49) Reconciliation to rate level (11) 12 (12) 13 Cost charged to operating expenses $62 $91 $54 $85

Other Postretirement Benefits (

Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2017
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 months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Service cost $5 $4 $3 $3 Interest cost on accumulated other postretirement benefit obligation 11 12 10 10 Expected return on plan assets (17) (19) (15) (17) Recognition of net actuarial loss 1 1 (1) 1 Recognition of prior service cost (4) (5) (3) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(4) $(7) $(6) $(7) Cost capitalized 2 2 2 2 Reconciliation to rate level (1) 7 — 7 Cost charged to operating expenses $(3) $2 $(4) $2

Environmental Matters (Tables)

Environmental Matters (Tables)	3 Months Ended
	Mar. 31, 2017
Environmental Remediation Obligations [Abstract]
Accrued Liabilities and Regulatory Assets	The accrued liabilities and regulatory assets related to Superfund Sites at March 31, 2017 and December 31, 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Accrued Liabilities: Manufactured gas plant sites $659 $664 $562 $567 Other Superfund Sites 87 89 87 88 Total $746 $753 $649 $655 Regulatory assets $808 $823 $697 $711
Environmental Remediation Costs	Environmental remediation costs incurred related to Superfund Sites for the three months ended March 31, 2017 and 2016 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Remediation costs incurred $7 $3 $7 $3
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 March 31, 2017 and December 31, 2016 were as follows: Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $88 $88 $84 $83 Regulatory assets – workers’ compensation $14 $13 $14 $13

Other Material Contingencies (T

Other Material Contingencies (Tables)	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of Total Guarantees	A summary, by type and term, of Con Edison’s total guarantees at March 31, 2017 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $460 $587 $— $1,047 Energy transactions 512 35 185 732 Renewable electric production projects 267 — 19 286 Other 128 — — 128 Total $1,367 $622 $204 $2,193

Financial Information by Busi31

Financial Information by Business Segment (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Financial Data for Business Segments	The financial data for the business segments are as follows: For the Three Months Ended March 31, Operating revenues Inter-segment revenues Depreciation and amortization Operating income/(loss) (Millions of Dollars) 2017 2016 2017 2016 2017 2016 2017 2016 CECONY Electric $1,793 $1,773 $5 $4 $229 $213 $292 $273 Gas 765 601 1 1 44 38 292 253 Steam 298 258 18 22 21 21 121 114 Consolidation adjustments — — (24) (27) — — — — Total CECONY $2,856 $2,632 $— $— $294 $272 $705 $640 O&R Electric $141 $140 $— $— $12 $12 $14 $18 Gas 97 75 — — 5 5 39 35 Total O&R $238 $215 $— $— $17 $17 $53 $53 Clean Energy Businesses $136 $310 $— $6 $17 $9 $15 $(51) Con Edison Transmission — — — — — — (3) — Other (a) (2) (1) — (6) 1 (1) 1 — Total Con Edison $3,228 $3,156 $— $— $329 $297 $771 $642 (a) Parent company and consolidation adjustments. Other does not represent a business segment.

Derivative Instruments and He32

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Offsetting of Liabilities	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2017 and December 31, 2016 were: (Millions of Dollars) 2017 2016 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 $71 $(39) $32 (b) $81 $(64) $17 (b) Noncurrent 19 (19) — 49 (43) 6 Total fair value of derivative assets $90 $(58) $32 $130 $(107) $23 Fair value of derivative liabilities Current $(117) $41 $(76) $(138) $61 $(77) Noncurrent (85) 19 (66) (91) 52 (39) (c) Total fair value of derivative liabilities $(202) $60 $(142) $(229) $113 $(116) Net fair value derivative assets/(liabilities) $(112) $2 $(110) (b) $(99) $6 $(93) (b) (c) CECONY Fair value of derivative assets Current $41 $(23) $18 (b) $52 $(45) $7 (b) Noncurrent 13 (13) — 41 (35) 6 Total fair value of derivative assets $54 $(36) $18 $93 $(80) $13 Fair value of derivative liabilities Current $(91) $28 $(63) $(111) $45 $(66) Noncurrent (73) 13 (60) (77) 44 (33) Total fair value of derivative liabilities $(164) $41 $(123) $(188) $89 $(99) Net fair value derivative assets/(liabilities) $(110) $5 $(105) (b) $(95) $9 $(86) (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 March 31, 2017 and December 31, 2016 , margin deposits for Con Edison ( $9 million and $7 million , respectively) and CECONY ( $9 million and $7 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include $(1) million for interest rate swap.
Offsetting of Assets	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2017 and December 31, 2016 were: (Millions of Dollars) 2017 2016 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 $71 $(39) $32 (b) $81 $(64) $17 (b) Noncurrent 19 (19) — 49 (43) 6 Total fair value of derivative assets $90 $(58) $32 $130 $(107) $23 Fair value of derivative liabilities Current $(117) $41 $(76) $(138) $61 $(77) Noncurrent (85) 19 (66) (91) 52 (39) (c) Total fair value of derivative liabilities $(202) $60 $(142) $(229) $113 $(116) Net fair value derivative assets/(liabilities) $(112) $2 $(110) (b) $(99) $6 $(93) (b) (c) CECONY Fair value of derivative assets Current $41 $(23) $18 (b) $52 $(45) $7 (b) Noncurrent 13 (13) — 41 (35) 6 Total fair value of derivative assets $54 $(36) $18 $93 $(80) $13 Fair value of derivative liabilities Current $(91) $28 $(63) $(111) $45 $(66) Noncurrent (73) 13 (60) (77) 44 (33) Total fair value of derivative liabilities $(164) $41 $(123) $(188) $89 $(99) Net fair value derivative assets/(liabilities) $(110) $5 $(105) (b) $(95) $9 $(86) (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 March 31, 2017 and December 31, 2016 , margin deposits for Con Edison ( $9 million and $7 million , respectively) and CECONY ( $9 million and $7 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Does not include $(1) million for interest rate swap.
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 months ended March 31, 2017 and 2016 : For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2017 2016 2017 2016 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $— $(4) $(2) $(4) Noncurrent Deferred derivative gains (3) — (3) (1) Total deferred gains/(losses) $(3) $(4) $(5) $(5) Current Deferred derivative losses $— $(30) $1 $(28) Current Recoverable energy costs (45) (73) (40) (66) Noncurrent Deferred derivative losses (20) (56) (20) (51) Total deferred gains/(losses) $(65) $(159) $(59) $(145) Net deferred gains/(losses) $(68) $(163) $(64) $(150) Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $— $(114) (b) $— $— Gas purchased for resale (63) (10) — — Non-utility revenue 14 (a) 11 (b) — — Total pre-tax gain/(loss) recognized in income $(49) $(113) $— $— (a) For the three months ended March 31, 2017 , Con Edison recorded unrealized pre-tax gains in non-utility operating revenue ( $3 million ). (b) For the three months ended March 31, 2016 , Con Edison recorded unrealized pre-tax losses in non-utility operating revenue ( $1 million loss) and purchased power expense ( $62 million loss).
Hedged Volume of Derivative Transactions	The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at March 31, 2017 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison 19,410,040 11,631 69,548,736 2,688,000 CECONY 17,605,375 6,000 62,210,000 2,688,000 (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 March 31, 2017 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $116 $106 Collateral posted 37 35 Additional collateral (b) (downgrade one level from current ratings) 17 16 Additional collateral (b) (downgrade to below investment grade from current ratings) 98 (c) 83 (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 Clean Energy Businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $12 million at March 31, 2017 . 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 liability 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 March 31, 2017 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $12 million .

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 and December 31, 2016 are summarized below. 2017 2016 (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) $12 $20 $6 $3 $41 $14 $33 $7 $(24) $30 Other (a)(b)(d) 240 114 — — 354 222 111 — — 333 Total assets $252 $134 $6 $3 $395 $236 $144 $7 $(24) $363 Derivative liabilities: Commodity (a)(b)(c) $5 $142 $3 $(8) $142 $4 $144 $6 $(38) $116 Interest Rate Swap (a)(b)(c) — — — — — — 1 — — 1 Total liabilities $5 $142 $3 $(8) $142 $4 $145 $6 $(38) $117 CECONY Derivative assets: Commodity (a)(b)(c) $5 $7 $1 $14 $27 $10 $19 $1 $(10) $20 Other (a)(b)(d) 217 109 — — 326 200 106 — — 306 Total assets $222 $116 $1 $14 $353 $210 $125 $1 $(10) $326 Derivative liabilities: Commodity (a)(b)(c) $— $122 $— $1 $123 $1 $124 $— $(26) $99 (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 three months ended March 31, 2017 and for the year ended December 31, 2016 . (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 March 31, 2017 and December 31, 2016 , 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.
Schedule of Commodity Derivatives	Fair Value of Level 3 at March 31, 2017 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $2 Discounted Cash Flow Forward energy prices (a) $21.75-$81.00 per MWh Discounted Cash Flow Forward capacity prices (a) $2.42-$10.70 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) 50.0% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (75.2)%-58.9% Inter-zonal forward price curves adjusted for historical zonal losses (b) $0.50-$10.26 per MWh Total Con Edison—Commodity $3 CECONY—Commodity Transmission Congestion Contracts $1 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 50.0% Discount/(premium) to adjust auction prices for historical monthly realized settlements (b) (75.2)%-58.9% (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 March 31, 2017 and 2016 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2017 2016 2017 2016 Beginning balance as of January 1, $1 $6 $1 $8 Included in earnings — (7) — (1) Included in regulatory assets and liabilities 2 (3) — (4) Settlements — — — (1) Ending balance as of March 31, $3 $(4) $1 $2

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2017
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 March 31, 2017 : 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 $173 Mesquite Solar 1 83 20 2013 Arizona 97 Copper Mountain Solar 2 75 25 2013 Nevada 80 California Solar 55 25 2012 California 59 Broken Bow II 38 25 2014 Nebraska 47 Texas Solar 4 32 25 2014 Texas 46 (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. With the exception of Texas Solar 4, 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. (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. For consolidated investments, such as Texas Solar 4, maximum exposure is equal to the net assets of the project on the consolidated balance sheet less any applicable noncontrolling interest ( $7 million for Texas Solar 4). Con Edison did not provide any financial or other support during the three months ended March 31, 2017 that was not previously contractually required.

General (Details)

General (Details)	3 Months Ended
	Mar. 31, 2017subsidiaryregistrant
Accounting Policies [Abstract]
Number of registrants | registrant	2
Number of regulated utility subsidiaries	2
Clean Energy Businesses
Investment [Line Items]
Number of subsidiaries	3

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accounting Policies [Abstract]
Net income	$ 388	$ 310
Weighted average common shares outstanding – basic	305.1	293.7
Add: Incremental shares attributable to effect of potentially dilutive securities	1.2	1.1
Adjusted weighted average common shares outstanding – diluted	306.3	294.8
Net income per common share-basic (dollars per share)	$ 1.27	$ 1.05
Net income per common share-diluted (dollars per share)	$ 1.27	$ 1.05

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Income/(Loss) by Component (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 14,306	$ 13,061
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	(1)	0
Ending Balance	14,506	13,201
CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	0	0
Accumulated OCI
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(27)	(34)
Ending Balance	(28)	(34)
Accumulated OCI | CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(7)	(9)
Ending Balance	(7)	(9)
Pension Plan Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
OCI before reclassifications, net of tax	(2)	(1)
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	1	1
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	(1)	0
OCI before reclassifications, tax	1	1
Amounts reclassified from accumulated OCI related to pension plan liabilities, tax	(1)	(1)
Pension Plan Liabilities | CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
OCI before reclassifications, net of tax	0	0
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax	0	0
TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES	$ 0	$ 0

Regulatory Matters - Summary of

Regulatory Matters - Summary of Utilities Rate Plans (Details) - Rockland Electric Company (RECO) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2016	Mar. 31, 2017
Public Utilities, General Disclosures [Line Items]
Base rate changes		$ 1.7
Amortization to income of net regulatory liabilities		$ 0.2
Regulatory liabilities, amortization period		3 years
Amortization to income of net regulatory assets		$ (25.6)
Regulatory assets, amortization period		4 years
Average rate base		$ 178.7
Weighted average cost of capital (after-tax) (percent)		7.47%
Authorized return on common equity (percent)		9.60%
Cost of long-term debt (percent)		5.37%
Common equity ratio (percent)		49.70%
Electric
Public Utilities, General Disclosures [Line Items]
Plan period (years)	3 years
Plan electric system storm hardening amount	$ 15.7

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Details) - FERC - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2017	Dec. 31, 2016
Public Utilities, General Disclosures [Line Items]
Requested return on equity (percent)	10.70%
Requested equity capital structure (percent)	48.00%
RECO
Public Utilities, General Disclosures [Line Items]
Requested rate increase, amount	$ 19.7	$ 11.8

Regulatory Matters - Regulatory

Regulatory Matters - Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	$ 1,854	$ 1,905
Regulatory liabilities – current	129	128
Total Regulatory Liabilities	1,983	2,033
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	7,074	7,024
Regulatory assets – current	95	100
Total Regulatory Assets	7,169	7,124
Allowance for cost of removal less salvage
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	772	755
Pension and other postretirement benefit deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	197	193
Property tax reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	162	178
Net unbilled revenue deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	104	145
Unrecognized other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	91	60
Settlement of prudence proceeding
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	87	95
Carrying charges on repair allowance and bonus depreciation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	62	68
New York State income tax rate change
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	56	61
Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	50	55
Base rate change deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	40
Settlement of gas proceedings
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	27	27
Earnings sharing - electric, gas and steam
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	20	39
Net utility plant reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	15	16
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	175	173
Refundable energy costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	60	29
Revenue decoupling mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	41	71
Deferred derivative gains
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	28	28
Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,911	2,874
Future income tax
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,434	2,439
Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	808	823
Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	307	295
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	68	48
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	53	56
Municipal infrastructure support cost
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	49	44
Indian Point Energy Center
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	48	50
Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	48	38
Surcharge for New York State assessment
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	45	28
Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	42	43
O&R property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	35	37
Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	29	42
Regulatory assets – current	4	9
Brooklyn Queens demand management program
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	28	29
Preferred stock redemption
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	25	25
Net electric deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	20	24
Workers’ compensation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	14	13
O&R transition bond charges
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	13	15
Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	97	101
Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – current	91	91
CECONY
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	1,654	1,712
Regulatory liabilities – current	96	90
Total Regulatory Liabilities	1,750	1,802
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	6,520	6,473
Regulatory assets – current	85	90
Total Regulatory Assets	6,605	6,563
CECONY | Allowance for cost of removal less salvage
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	649	641
CECONY | Pension and other postretirement benefit deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	167	162
CECONY | Property tax reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	162	178
CECONY | Net unbilled revenue deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	104	145
CECONY | Unrecognized other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	91	60
CECONY | Settlement of prudence proceeding
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	87	95
CECONY | Carrying charges on repair allowance and bonus depreciation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	61	67
CECONY | New York State income tax rate change
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	55	60
CECONY | Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	44	48
CECONY | Base rate change deferrals
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	36	40
CECONY | Settlement of gas proceedings
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	27	27
CECONY | Earnings sharing - electric, gas and steam
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	10	28
CECONY | Net utility plant reconciliations
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	13	15
CECONY | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities – noncurrent	148	146
CECONY | Refundable energy costs
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	36	5
CECONY | Revenue decoupling mechanism
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	38	61
CECONY | Deferred derivative gains
Regulatory Liabilities [Line Items]
Regulatory liabilities – current	22	24
CECONY | Unrecognized pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,748	2,730
CECONY | Future income tax
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	2,321	2,325
CECONY | Environmental remediation costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	697	711
CECONY | Revenue taxes
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	291	280
CECONY | Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	62	42
CECONY | Deferred storm costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	3	3
CECONY | Municipal infrastructure support cost
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	49	44
CECONY | Indian Point Energy Center
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	48	50
CECONY | Pension and other postretirement benefits deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	19	7
CECONY | Surcharge for New York State assessment
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	42	26
CECONY | Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	40	41
CECONY | O&R property tax reconciliation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	0
CECONY | Recoverable energy costs
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	26	38
Regulatory assets – current	0	4
CECONY | Brooklyn Queens demand management program
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	28	29
CECONY | Preferred stock redemption
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	25	25
CECONY | Net electric deferrals
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	20	24
CECONY | Workers’ compensation
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	14	13
CECONY | O&R transition bond charges
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	0	0
CECONY | Other
Regulatory Assets [Line Items]
Regulatory assets – noncurrent	87	85
CECONY | Deferred derivative losses
Regulatory Assets [Line Items]
Regulatory assets – current	$ 85	$ 86

Capitalization - Additional Inf

Capitalization - Additional Information (Details)	1 Months Ended	3 Months Ended
	Mar. 31, 2017USD ($)	Mar. 31, 2017USD ($)
Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value	$ 15,570,000,000	$ 15,570,000,000
Level 3
Schedule of Capitalization [Line Items]
Long-term debt, fair value	636,000,000	636,000,000
CECONY | Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value	12,652,000,000	12,652,000,000
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
Variable Rate Term Loan Due 2018 | Term Loan
Schedule of Capitalization [Line Items]
Amount of debt prepaid	400,000,000
Debentures | 2.00% Debentures Due 2020
Schedule of Capitalization [Line Items]
Debt Instrument, face amount	$ 400,000,000	$ 400,000,000
Debt instrument, interest rate	2.00%	2.00%
Senior Notes | 4.45% Senior Notes Due 2042 | Con Edison Development
Schedule of Capitalization [Line Items]
Debt Instrument, face amount	$ 97,000,000	$ 97,000,000
Debt instrument, interest rate	4.45%	4.45%

Capitalization - Carrying Amoun

Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	$ 14,862	$ 14,774
Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	16,206	16,093
CECONY | Carrying Amount
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	12,075	12,073
CECONY | Fair Value
Debt Instrument [Line Items]
Long-Term Debt (including current portion)	$ 13,288	$ 13,268

Short-Term Borrowing (Details)

Short-Term Borrowing (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 836,000,000	$ 1,054,000,000
Weighted average interest rate (percent)	1.10%	1.00%
Loans outstanding under credit agreement	$ 0	$ 0
Letters of credit outstanding under the Credit Agreement	0	2,000,000
CECONY
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 445,000,000	$ 600,000,000
Weighted average interest rate (percent)	1.10%	1.00%
Letters of credit outstanding under the Credit Agreement	$ 0	$ 2,000,000

Pension Benefits - Total Period

Pension Benefits - Total Periodic Benefit Costs (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 66	$ 69
Interest cost on projected benefit obligation	148	149
Expected return on plan assets	(243)	(237)
Recognition of net actuarial loss	149	149
Recognition of prior service costs	(4)	1
TOTAL PERIODIC BENEFIT COST	116	131
Cost capitalized	(43)	(52)
Reconciliation to rate level	(11)	12
Cost charged to operating expenses	62	91
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	61	65
Interest cost on projected benefit obligation	139	140
Expected return on plan assets	(229)	(225)
Recognition of net actuarial loss	141	141
Recognition of prior service costs	(5)	0
TOTAL PERIODIC BENEFIT COST	107	121
Cost capitalized	(41)	(49)
Reconciliation to rate level	(12)	13
Cost charged to operating expenses	$ 54	$ 85

Pension Benefits - Additional I

Pension Benefits - Additional Information (Details) - Pension Benefits $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions	$ 450
Contributions	129
CECONY
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions	$ 412

Other Postretirement Benefits -

Other Postretirement Benefits - Total Periodic Postretirement Benefit Costs (Details) - Other Postretirement Benefits - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5	$ 4
Interest cost on accumulated other postretirement benefit obligation	11	12
Expected return on plan assets	(17)	(19)
Recognition of net actuarial loss	1	1
Recognition of prior service cost	(4)	(5)
TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST	(4)	(7)
Cost capitalized	2	2
Reconciliation to rate level	(1)	7
Cost charged to operating expenses	(3)	2
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	3
Interest cost on accumulated other postretirement benefit obligation	10	10
Expected return on plan assets	(15)	(17)
Recognition of net actuarial loss	(1)	1
Recognition of prior service cost	(3)	(4)
TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST	(6)	(7)
Cost capitalized	2	2
Reconciliation to rate level	0	7
Cost charged to operating expenses	$ (4)	$ 2

Other Postretirement Benefits47

Other Postretirement Benefits - Additional Information (Details) - Other Postretirement Benefits $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 16
CECONY
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 8

Environmental Matters - Accrued

Environmental Matters - Accrued Liabilities and Regulatory Assets (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Site Contingency [Line Items]
Accrued Liabilities	$ 746	$ 753
Regulatory assets	7,169	7,124
Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	659	664
Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	87	89
Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	746	753
Regulatory assets	808	823
CECONY
Site Contingency [Line Items]
Accrued Liabilities	649	655
Regulatory assets	6,605	6,563
CECONY | Manufactured gas plant sites
Site Contingency [Line Items]
Accrued Liabilities	562	567
CECONY | Other Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	87	88
CECONY | Superfund Sites
Site Contingency [Line Items]
Accrued Liabilities	649	655
Regulatory assets	$ 697	$ 711

Environmental Matters - Environ

Environmental Matters - Environmental Remediation Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 7	$ 3
CECONY
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 7	$ 3

Environmental Matters - Additio

Environmental Matters - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Site Contingency [Line Items]
Insurance recoveries	$ 0	$ 0
CECONY
Site Contingency [Line Items]
Insurance recoveries	$ 0	$ 0
CECONY | Asbestos Proceedings
Site Contingency [Line Items]
Estimated undiscounted asbestos liability (years)	15 years
Superfund Sites | Manufactured Gas Plant Sites | Maximum
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)			$ 2,800,000,000
Superfund Sites | Manufactured Gas Plant Sites | Maximum | CECONY
Site Contingency [Line Items]
Estimated aggregate undiscounted potential liability related environmental contaminants (up to)			$ 2,600,000,000

Environmental Matters - Accru51

Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Site Contingency [Line Items]
Regulatory assets	$ 7,169	$ 7,124
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers’ Compensation
Site Contingency [Line Items]
Accrued liability	88	88
Regulatory assets	14	13
CECONY
Site Contingency [Line Items]
Regulatory assets	6,605	6,563
CECONY | Asbestos Suits
Site Contingency [Line Items]
Accrued liability	7	7
Regulatory assets	7	7
CECONY | Workers’ Compensation
Site Contingency [Line Items]
Accrued liability	84	83
Regulatory assets	$ 14	$ 13

Other Material Contingencies -

Other Material Contingencies - Manhattan Steam Main Rupture (Details) - CECONY - Manhattan Steam Main Rupture $ in Millions	1 Months Ended
	Jul. 31, 2007person	Mar. 31, 2017USD ($)lawsuit
Loss Contingencies [Line Items]
Number of person who died in stream rupture incident | person	1
Number of pending lawsuits | lawsuit		55
Estimated accrued liability for suits		$ 25
Insurance receivable for suits		$ 25

Other Material Contingencies Ot

Other Material Contingencies Other Material Contingencies - Manhattan Explosion and Fire (Details) $ in Millions	Mar. 12, 2014buildingpeople	Feb. 28, 2017USD ($)	Mar. 31, 2017USD ($)lawsuit	Dec. 31, 2016USD ($)
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 1,854	$ 1,905
Settlement of Gas Proceedings
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 27	$ 27
Manhattan Explosion and Fire
Loss Contingencies [Line Items]
Number of buildings destroyed by fire | building	2
Number of people died in explosion and fire incident | people	8
Number of people injured in explosion and fire incident (more than) | people	50
Amount of costs that will not recover from customers		$ 126
Number of pending lawsuits | lawsuit			80
Manhattan Explosion and Fire | Settlement of Gas Proceedings
Loss Contingencies [Line Items]
Accrued regulatory liability			$ 27

Other Material Contingencies 54

Other Material Contingencies - Total Guarantees (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 2,193	$ 2,370
Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	1,047
Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	732
Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	286
Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	128
0 – 3 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	1,367
0 – 3 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	460
0 – 3 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	512
0 – 3 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	267
0 – 3 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	128
4 – 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	622
4 – 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	587
4 – 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	35
4 – 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
4 – 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
Greater than 10 years
Guarantor Obligations [Line Items]
Total guarantees, by type and term	204
Greater than 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Total guarantees, by type and term	0
Greater than 10 years | Energy transactions
Guarantor Obligations [Line Items]
Total guarantees, by type and term	185
Greater than 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Total guarantees, by type and term	19
Greater than 10 years | Other
Guarantor Obligations [Line Items]
Total guarantees, by type and term	$ 0

Other Material Contingencies 55

Other Material Contingencies Other Material Contingencies - Con Edison Transmission (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,193	$ 2,370
Payment Guarantee by CET Electric of Contributions to New York Transco LLC
Guarantor Obligations [Line Items]
Ownership interest, percentage			45.70%
Estimated project cost percentage	175.00%
Financial Guarantee in Behalf of CET Gas for Proposed Gas Transmission Project
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 25

Other Material Contingencies 56

Other Material Contingencies Other Material Contingencies - Energy Transactions (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,193	$ 2,370
Financial and Performance Guarantee for Commodity Transactions During Period in which Con Edison Solutions Provides Transition Services
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 21

Other Material Contingencies 57

Other Material Contingencies Other Material Contingencies - Other (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,193	$ 2,370
Financial Guarantee for Indemnity Agreements for Surety Bonds
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	70
Certain Obligations Under Agreement to Sell the Retail Electric Supply Business
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	53
Financial Guarantee to Public Utility Commission of Texas
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 5

Income Tax (Details)

Income Tax (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Taxes Disclosure [Line Items]
Income taxes on operating income	$ 227,000,000	$ 164,000,000
Effective tax rate	37.00%	35.00%
Deferred tax asset, net operating loss	$ 22,000,000
Valuation allowance	0
Estimated liability for uncertain tax positions	40,000,000
Effective income tax rate reconciliation, uncertainty of taxes	33,000,000
Effective income tax rate reconciliation, uncertainty net of federal taxes	23,000,000
Unrecognized tax benefits that would have an impact on effective tax rate	19,000,000
Unrecognized tax benefits that would have an impact on effective tax rate, net of taxes	13,000,000
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate	23,000,000
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate, net of federal taxes	16,000,000
Penalties for uncertain tax positions	0
CECONY
Income Taxes Disclosure [Line Items]
Income taxes on operating income	$ 218,000,000	$ 180,000,000
Effective tax rate	39.00%	37.00%
Estimated liability for uncertain tax positions	$ 21,000,000
Effective income tax rate reconciliation, uncertainty of taxes	17,000,000
Effective income tax rate reconciliation, uncertainty net of federal taxes	12,000,000
Unrecognized tax benefits that would have an impact on effective tax rate	$ 2,000,000

Financial Information by Busi59

Financial Information by Business Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 3,228	$ 3,156
Depreciation and amortization	329	297
Operating income/(loss)	771	642
Clean Energy Businesses
Segment Reporting Information [Line Items]
Depreciation and amortization	17	9
Operating income/(loss)	15	(51)
Con Edison Transmission
Segment Reporting Information [Line Items]
Operating income/(loss)	(3)	0
CECONY
Segment Reporting Information [Line Items]
Revenues	2,856	2,632
Depreciation and amortization	294	272
Operating income/(loss)	705	640
CECONY | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	229	213
Operating income/(loss)	292	273
CECONY | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	44	38
Operating income/(loss)	292	253
CECONY | Steam
Segment Reporting Information [Line Items]
Depreciation and amortization	21	21
Operating income/(loss)	121	114
O&R
Segment Reporting Information [Line Items]
Depreciation and amortization	17	17
Operating income/(loss)	53	53
O&R | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	12	12
Operating income/(loss)	14	18
O&R | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	5	5
Operating income/(loss)	39	35
Operating segment
Segment Reporting Information [Line Items]
Revenues	3,228	3,156
Operating segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Revenues	136	310
Operating segment | CECONY
Segment Reporting Information [Line Items]
Revenues	2,856	2,632
Operating segment | CECONY | Electric
Segment Reporting Information [Line Items]
Revenues	1,793	1,773
Operating segment | CECONY | Gas
Segment Reporting Information [Line Items]
Revenues	765	601
Operating segment | CECONY | Steam
Segment Reporting Information [Line Items]
Revenues	298	258
Operating segment | O&R
Segment Reporting Information [Line Items]
Revenues	238	215
Operating segment | O&R | Electric
Segment Reporting Information [Line Items]
Revenues	141	140
Operating segment | O&R | Gas
Segment Reporting Information [Line Items]
Revenues	97	75
Other
Segment Reporting Information [Line Items]
Revenues	(2)	(1)
Depreciation and amortization	1	(1)
Operating income/(loss)	1	0
Inter-segment
Segment Reporting Information [Line Items]
Revenues	0	(6)
Inter-segment | Clean Energy Businesses
Segment Reporting Information [Line Items]
Revenues	0	6
Inter-segment | CECONY
Segment Reporting Information [Line Items]
Revenues	(24)	(27)
Inter-segment | CECONY | Electric
Segment Reporting Information [Line Items]
Revenues	5	4
Inter-segment | CECONY | Gas
Segment Reporting Information [Line Items]
Revenues	1	1
Inter-segment | CECONY | Steam
Segment Reporting Information [Line Items]
Revenues	$ 18	$ 22

Derivative Instruments and He60

Derivative Instruments and Hedging Activities - Fair Values of Commodity Derivatives Including Offsetting of Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Net fair value derivative assets/(liabilities)
Gross Amounts of Recognized Assets/ (Liabilities)	$ (112)	$ (99)
Gross Amounts Offset	2	6
Net Amounts of Assets/ (Liabilities)	(110)	(93)
Margin deposits	9	7
Interest Rate Swap
Fair value of derivative liabilities
Net Amounts of Assets/ (Liabilities)		(1)
CECONY
Net fair value derivative assets/(liabilities)
Gross Amounts of Recognized Assets/ (Liabilities)	(110)	(95)
Gross Amounts Offset	5	9
Net Amounts of Assets/ (Liabilities)	(105)	(86)
Margin deposits	9	7
Fair Value of Derivative Liabilities, Current
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(117)	(138)
Gross Amounts Offset	41	61
Net Amounts of Assets/ (Liabilities)	(76)	(77)
Fair Value of Derivative Liabilities, Current | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(91)	(111)
Gross Amounts Offset	28	45
Net Amounts of Assets/ (Liabilities)	(63)	(66)
Fair Value of Derivative Liabilities, Non-current
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(85)	(91)
Gross Amounts Offset	19	52
Net Amounts of Assets/ (Liabilities)	(66)	(39)
Fair Value of Derivative Liabilities, Non-current | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(73)	(77)
Gross Amounts Offset	13	44
Net Amounts of Assets/ (Liabilities)	(60)	(33)
Fair Value of Derivative Liabilities
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(202)	(229)
Gross Amounts Offset	60	113
Net Amounts of Assets/ (Liabilities)	(142)	(116)
Fair Value of Derivative Liabilities | CECONY
Fair value of derivative liabilities
Gross Amounts of Recognized Assets/ (Liabilities)	(164)	(188)
Gross Amounts Offset	41	89
Net Amounts of Assets/ (Liabilities)	(123)	(99)
Fair Value of Derivative Assets, Current
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	71	81
Gross Amounts Offset	(39)	(64)
Net Amounts of Assets/ (Liabilities)	32	17
Fair Value of Derivative Assets, Current | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	41	52
Gross Amounts Offset	(23)	(45)
Net Amounts of Assets/ (Liabilities)	18	7
Fair Value of Derivative Assets, Non-current
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	19	49
Gross Amounts Offset	(19)	(43)
Net Amounts of Assets/ (Liabilities)	0	6
Fair Value of Derivative Assets, Non-current | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	13	41
Gross Amounts Offset	(13)	(35)
Net Amounts of Assets/ (Liabilities)	0	6
Fair Value of Derivative Assets
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	90	130
Gross Amounts Offset	(58)	(107)
Net Amounts of Assets/ (Liabilities)	32	23
Fair Value of Derivative Assets | CECONY
Fair value of derivative assets
Gross Amounts of Recognized Assets/ (Liabilities)	54	93
Gross Amounts Offset	(36)	(80)
Net Amounts of Assets/ (Liabilities)	$ 18	$ 13

Derivative Instruments and He61

Derivative Instruments and Hedging Activities - Realized and Unrealized Gains or Losses on Commodity Derivatives (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ (3)	$ (4)
Total deferred gains/(losses)	(65)	(159)
Net deferred gains/(losses)	(68)	(163)
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(49)	(113)
Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	(114)
Unrealized gain/(loss) on derivatives		(62)
Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(63)	(10)
Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	14	11
Non-utility operating revenue
Pre-tax gain/(loss) recognized in income
Unrealized gain/(loss) on derivatives	3	1
Deferred Derivative Gains,Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	0	(4)
Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(3)	0
Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	0	(30)
Recoverable Energy Costs, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(45)	(73)
Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(20)	(56)
CECONY
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(5)	(5)
Total deferred gains/(losses)	(59)	(145)
Net deferred gains/(losses)	(64)	(150)
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	0	0
CECONY | Deferred Derivative Gains,Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(2)	(4)
CECONY | Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(3)	(1)
CECONY | Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	1	(28)
CECONY | Recoverable Energy Costs, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(40)	(66)
CECONY | Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ (20)	$ (51)

Derivative Instruments and He62

Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Details) gal in Thousands	Mar. 31, 2017galMMBTUMWMWh
Electric Energy
Derivatives, Fair Value [Line Items]
Notional amount | MWh	19,410,040
Capacity
Derivatives, Fair Value [Line Items]
Notional amount | MW	11,631
Natural Gas
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	69,548,736
Refined Fuels
Derivatives, Fair Value [Line Items]
Notional amount | gal	2,688
CECONY | Electric Energy
Derivatives, Fair Value [Line Items]
Notional amount | MWh	17,605,375
CECONY | Capacity
Derivatives, Fair Value [Line Items]
Notional amount | MW	6,000
CECONY | Natural Gas
Derivatives, Fair Value [Line Items]
Notional amount | MMBTU	62,210,000
CECONY | Refined Fuels
Derivatives, Fair Value [Line Items]
Notional amount | gal	2,688

Derivative Instruments and He63

Derivative Instruments and Hedging Activities - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 63
Makeup of net credit exposure with investment-grade counterparties	20
Makeup of net credit exposure with commodity exchange brokers	20
Makeup of net credit exposure non-investment grade/non-rated counterparties	16
Makeup of net credit exposure independent system operators	7
Interest Rate Swap
Investment Holdings [Line Items]
Derivative liabilities		$ 1
CECONY
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	10
Makeup of net credit exposure with investment-grade counterparties	1
Makeup of net credit exposure with commodity exchange brokers	9
Clean Energy Businesses | Coram | Interest Rate Swap
Investment Holdings [Line Items]
Derivative, fixed interest rate		2.0855%
Derivative liabilities	$ 0	$ 1

Derivative Instruments and He64

Derivative Instruments and Hedging Activities - Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features (Details) $ in Millions	Mar. 31, 2017USD ($)
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	$ 116
Collateral posted	37
Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	17
Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	98
Derivatives in net asset position additional collateral	12
Additional Collateral Required Due To Loss Of Unsecured Credit
Derivatives, Fair Value [Line Items]
Collateral posted	12
CECONY
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	106
Collateral posted	35
CECONY | Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	16
CECONY | Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Additional collateral	$ 83

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		$ 1
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 395	363
Total liabilities	142	117
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	252	236
Total liabilities	5	4
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	134	144
Total liabilities	142	145
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	6	7
Total liabilities	3	6
Recurring | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	41	30
Derivative liabilities	142	116
Recurring | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	27	20
Total assets	353	326
Derivative liabilities	123	99
Recurring | Commodity | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	12	14
Derivative liabilities	5	4
Recurring | Commodity | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	5	10
Total assets	222	210
Derivative liabilities	0	1
Recurring | Commodity | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	20	33
Derivative liabilities	142	144
Recurring | Commodity | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	7	19
Total assets	116	125
Derivative liabilities	122	124
Recurring | Commodity | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6	7
Derivative liabilities	3	6
Recurring | Commodity | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1	1
Total assets	1	1
Derivative liabilities	0	0
Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	354	333
Recurring | Other | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	326	306
Recurring | Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	240	222
Recurring | Other | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	217	200
Recurring | Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	114	111
Recurring | Other | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	109	106
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 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	1
Recurring | Interest Rate Swap | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Interest Rate Swap | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	1
Recurring | Interest Rate Swap | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Netting Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	3	(24)
Total liabilities	(8)	(38)
Recurring | Netting Adjustments | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3	(24)
Derivative liabilities	(8)	(38)
Recurring | Netting Adjustments | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	14	(10)
Total assets	14	(10)
Derivative liabilities	1	(26)
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
Recurring | Netting Adjustments | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Commodity Derivatives (Details) - Level 3 $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)$ / kW-month$ / MWh
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 3
Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 2
Electricity | Forward Energy Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	21.75
Electricity | Forward Energy Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / MWh	81
Electricity | Forward Capacity Prices | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / kW-month	2.42
Electricity | Forward Capacity Prices | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH) | $ / kW-month	10.70
Transmission Congestion Contracts/Financial Transmission Rights
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 1
Transmission Congestion Contracts/Financial Transmission Rights | Discount for Inter Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	50.00%
Transmission Congestion Contracts/Financial Transmission Rights | Discount for Historical Monthly Realized Settlements | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	(75.20%)
Transmission Congestion Contracts/Financial Transmission Rights | Discount for Historical Monthly Realized Settlements | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	58.90%
Transmission Congestion Contracts/Financial Transmission Rights | Inter Zonal Forward Price Curves Adjusted for Historical Zonal Losses | Minimum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	0.50
Transmission Congestion Contracts/Financial Transmission Rights | Inter Zonal Forward Price Curves Adjusted for Historical Zonal Losses | Maximum
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	10.26
Transmission Congestion Contracts | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 1
Transmission Congestion Contracts | Discount for Inter Zonal Forward Price Curves | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	50.00%
Transmission Congestion Contracts | Discount for Historical Monthly Realized Settlements | Minimum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	(75.20%)
Transmission Congestion Contracts | Discount for Historical Monthly Realized Settlements | Maximum | CECONY
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	58.90%

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1	$ 6
Included in earnings	0	(7)
Included in regulatory assets and liabilities	2	(3)
Settlements	0	0
Ending balance	3	(4)
CECONY
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1	8
Included in earnings	0	(1)
Included in regulatory assets and liabilities	0	(4)
Settlements	0	(1)
Ending balance	$ 1	$ 2

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - Purchased power expense - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, assets measured on recurring basis, change in unrealized loss	$ 0	$ 4
Clean Energy Businesses
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loss on Level 3 energy derivative liabilities	$ 0	$ 6

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Details)	Dec. 31, 2016entity
CECONY
Variable Interest Entity [Line Items]
Number of potential VIEs, long-term electricity purchase agreements	2

Variable Interest Entities - Su

Variable Interest Entities - Summary of VIEs (Details)	3 Months Ended
	Mar. 31, 2017USD ($)MW
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 3 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	128
Power Purchase Agreement Term (in Years)	20 years
Maximum Exposure to Loss	$ 173,000,000
Variable Interest Entity, Not Primary Beneficiary | Mesquite Solar 1 | Arizona
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	83
Power Purchase Agreement Term (in Years)	20 years
Maximum Exposure to Loss	$ 97,000,000
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 2 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	75
Power Purchase Agreement Term (in Years)	25 years
Maximum Exposure to Loss	$ 80,000,000
Variable Interest Entity, Not Primary Beneficiary | California Solar | California
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	55
Power Purchase Agreement Term (in Years)	25 years
Maximum Exposure to Loss	$ 59,000,000
Variable Interest Entity, Not Primary Beneficiary | Broken Bow II | Nebraska
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	38
Power Purchase Agreement Term (in Years)	25 years
Maximum Exposure to Loss	$ 47,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4
Variable Interest Entity [Line Items]
Percentage of variable interests	80.00%
Maximum exposure for consolidated investments	$ 7,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4 | Texas
Variable Interest Entity [Line Items]
Generating Capacity (MW AC) | MW	32
Power Purchase Agreement Term (in Years)	25 years
Maximum Exposure to Loss	$ 46,000,000
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Percentage of variable interests	50.00%