Consolidated Edison Co Of New York 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 29, 2016
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
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		293,996,588
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, 2016	Mar. 31, 2015
OPERATING REVENUES
Electric	$ 1,912	$ 2,135
Gas	676	732
Steam	258	375
Non-utility	310	374
TOTAL OPERATING REVENUES	3,156	3,616
OPERATING EXPENSES
Purchased power	691	884
Fuel	71	154
Gas purchased for resale	158	262
Other operations and maintenance	787	814
Depreciation and amortization	297	279
Taxes, other than income taxes	510	497
TOTAL OPERATING EXPENSES	2,514	2,890
OPERATING INCOME	642	726
OTHER INCOME (DEDUCTIONS)
Investment and other income	4	5
Allowance for equity funds used during construction	2	1
Other deductions	(5)	(2)
TOTAL OTHER INCOME	1	4
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	643	730
INTEREST EXPENSE
Interest on long-term debt	163	156
Other interest	7	6
Allowance for borrowed funds used during construction	(1)	(1)
NET INTEREST EXPENSE	169	161
INCOME BEFORE INCOME TAX EXPENSE	474	569
INCOME TAX EXPENSE	164	199
NET INCOME	$ 310	$ 370
Net income per common share-basic (dollars per share)	$ 1.05	$ 1.26
Net income per common share-diluted (dollars per share)	1.05	1.26
DIVIDENDS DECLARED PER COMMON SHARE (dollars per share)	$ 0.67	$ 0.65
AVERAGE NUMBER OF SHARES OUTSTANDING-BASIC (IN MILLIONS) (shares)	293.7	292.9
AVERAGE NUMBER OF SHARES OUTSTANDING-DILUTED (IN MILLIONS) (shares)	294.8	293.9
CECONY
OPERATING REVENUES
Electric	$ 1,773	$ 1,980
Gas	601	655
Steam	258	375
TOTAL OPERATING REVENUES	2,632	3,010
OPERATING EXPENSES
Purchased power	352	539
Fuel	71	154
Gas purchased for resale	132	198
Other operations and maintenance	681	703
Depreciation and amortization	272	257
Taxes, other than income taxes	484	475
TOTAL OPERATING EXPENSES	1,992	2,326
OPERATING INCOME	640	684
OTHER INCOME (DEDUCTIONS)
Investment and other income	1	2
Allowance for equity funds used during construction	2	1
Other deductions	(5)	(2)
TOTAL OTHER INCOME	(2)	1
INCOME BEFORE INTEREST AND INCOME TAX EXPENSE	638	685
INTEREST EXPENSE
Interest on long-term debt	144	141
Other interest	5	4
Allowance for borrowed funds used during construction	(1)	0
NET INTEREST EXPENSE	148	145
INCOME BEFORE INCOME TAX EXPENSE	490	540
INCOME TAX EXPENSE	180	192
NET INCOME	$ 310	$ 348

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
NET INCOME	$ 310	$ 370
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	0	5
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	0	5
COMPREHENSIVE INCOME	310	375
CECONY
NET INCOME	310	348
OTHER COMPREHENSIVE INCOME, NET OF TAXES
Pension and other postretirement benefit plan liability adjustments, net of taxes	0	0
TOTAL OTHER COMPREHENSIVE INCOME, NET OF TAXES	0	0
COMPREHENSIVE INCOME	$ 310	$ 348

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING ACTIVITIES
NET INCOME	$ 310	$ 370
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	297	279
Deferred income taxes	174	178
Rate case amortization and accruals	(63)	(8)
Common equity component of allowance for funds used during construction	(2)	(1)
Net derivative (gains)/losses	64	(8)
Other non-cash items, net	35	5
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(30)	(243)
Materials and supplies, including fuel oil and gas in storage	8	40
Other receivables and other current assets	(40)	(3)
Income taxes receivable	151	224
Prepayments	(374)	(307)
Accounts payable	(84)	(58)
Pensions and retiree benefits obligations, net	139	185
Pensions and retiree benefits contributions	(153)	(204)
Accrued taxes	(11)	8
Accrued interest	54	48
Superfund and environmental remediation costs, net	55	8
Distributions from equity investments	24	17
Deferred charges, noncurrent assets and other regulatory assets	(149)	29
Deferred credits and other regulatory liabilities	110	33
Other current and noncurrent liabilities	9	(33)
NET CASH FLOWS FROM OPERATING ACTIVITIES	524	559
INVESTING ACTIVITIES
Utility construction expenditures	(603)	(550)
Cost of removal less salvage	(44)	(50)
Non-utility construction expenditures	(210)	(42)
Investments in/acquisitions of renewable electric production and gas transmission projects	(247)	(35)
Restricted cash	(1)	4
Other investing activities	(13)	6
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(1,118)	(667)
FINANCING ACTIVITIES
Net payment of short-term debt	(330)	(281)
Issuance of long-term debt	218	0
Retirement of long-term debt	(1)	0
Debt issuance costs	(3)	(1)
Common stock dividends	(185)	(190)
Issuance of common shares for stock plans, net of repurchases	15	(2)
Distribution to noncontrolling interest	(1)	0
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(287)	(474)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(881)	(582)
BALANCE AT BEGINNING OF PERIOD	944	699
BALANCE AT END OF PERIOD	63	117
LESS: CHANGE IN CASH BALANCES HELD FOR SALE	2	0
BALANCE AT BEGINNING OF PERIOD	944
BALANCE AT END OF PERIOD	61	117
Cash paid/(received) during the period for:
Interest	109	105
Income taxes	(143)	(197)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	263	190
Issuance of common shares for dividend reinvestment	12	3
CECONY
OPERATING ACTIVITIES
NET INCOME	310	348
PRINCIPAL NON-CASH CHARGES/(CREDITS) TO INCOME
Depreciation and amortization	272	257
Deferred income taxes	236	127
Rate case amortization and accruals	(67)	(14)
Common equity component of allowance for funds used during construction	(2)	(1)
Other non-cash items, net	16	1
CHANGES IN ASSETS AND LIABILITIES
Accounts receivable – customers	(30)	(196)
Materials and supplies, including fuel oil and gas in storage	18	40
Other receivables and other current assets	13	57
Accounts receivable from affiliated companies	71	108
Prepayments	(324)	(278)
Accounts payable	(106)	(48)
Pensions and retiree benefits obligations, net	132	178
Pensions and retiree benefits contributions	(153)	(203)
Accrued taxes	(10)	0
Accrued interest	41	39
Superfund and environmental remediation costs, net	55	7
Accrued taxes to affiliated companies	(2)	25
Deferred charges, noncurrent assets and other regulatory assets	(148)	28
Deferred credits and other regulatory liabilities	111	43
Other current and noncurrent liabilities	25	(38)
NET CASH FLOWS FROM OPERATING ACTIVITIES	458	480
INVESTING ACTIVITIES
Utility construction expenditures	(565)	(519)
Cost of removal less salvage	(43)	(49)
Restricted cash	2	0
NET CASH FLOWS USED IN INVESTING ACTIVITIES	(606)	(568)
FINANCING ACTIVITIES
Net payment of short-term debt	(513)	(182)
Debt issuance costs	(1)	(1)
Capital contribution by parent	23	0
Dividend to parent	(186)	(338)
NET CASH FLOWS USED IN FINANCING ACTIVITIES	(677)	(521)
CASH AND TEMPORARY CASH INVESTMENTS:
NET CHANGE FOR THE PERIOD	(825)	(609)
BALANCE AT BEGINNING OF PERIOD	843	645
BALANCE AT END OF PERIOD	18	36
Cash paid/(received) during the period for:
Interest	100	99
Income taxes	(143)	(86)
SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION
Construction expenditures in accounts payable	$ 210	$ 138

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
CURRENT ASSETS
Cash and temporary cash investments	$ 61	$ 944
Special deposits	10	3
Accounts receivable - customers, less allowance for uncollectible accounts	1,085	1,052
Other receivables, less allowance for uncollectible accounts	362	304
Income taxes receivable	15	166
Accrued unbilled revenue	285	360
Fuel oil, gas in storage, materials and supplies, at average cost	342	350
Prepayments	550	177
Regulatory assets	152	132
Assets held for sale	166	157
Other current assets	157	191
TOTAL CURRENT ASSETS	3,185	3,836
INVESTMENTS	865	884
UTILITY PLANT, AT ORIGINAL COST
General	2,625	2,622
TOTAL	38,564	38,174
Less: Accumulated depreciation	8,174	8,044
Net	30,390	30,130
Construction work in progress	1,115	1,003
NET UTILITY PLANT	31,505	31,133
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	859	832
Construction work in progress	607	244
NET PLANT	32,971	32,209
OTHER NONCURRENT ASSETS
Goodwill	429	429
Intangible assets, less accumulated amortization of $5 and $4 in 2016 and 2015, respectively	2	2
Regulatory assets	7,930	8,096
Other deferred charges and noncurrent assets	198	186
TOTAL OTHER NONCURRENT ASSETS	8,559	8,713
TOTAL ASSETS	45,580	45,642
CURRENT LIABILITIES
Long-term debt due within one year	739	739
Notes payable	1,199	1,529
Accounts payable	909	1,008
Customer deposits	356	354
Accrued taxes	51	62
Accrued interest	190	136
Accrued wages	98	97
Fair value of derivative liabilities	90	66
Regulatory liabilities	125	115
Liabilities held for sale	150	89
Other current liabilities	529	525
TOTAL CURRENT LIABILITIES	4,436	4,720
NONCURRENT LIABILITIES
Provision for injuries and damages	193	185
Pensions and retiree benefits	2,599	2,911
Superfund and other environmental costs	767	765
Asset retirement obligations	247	242
Fair value of derivative liabilities	92	39
Deferred income taxes and unamortized investment tax credits	9,770	9,537
Regulatory liabilities	1,858	1,977
Other deferred credits and noncurrent liabilities	195	199
TOTAL NONCURRENT LIABILITIES	15,721	15,855
LONG-TERM DEBT	12,222	12,006
EQUITY
Common shareholders’ equity	13,193	13,052
Noncontrolling interest	8	9
TOTAL EQUITY (See Statement of Equity)	13,201	13,061
TOTAL LIABILITIES AND EQUITY	45,580	45,642
CECONY
CURRENT ASSETS
Cash and temporary cash investments	18	843
Special deposits	2	2
Accounts receivable - customers, less allowance for uncollectible accounts	1,022	987
Other receivables, less allowance for uncollectible accounts	80	70
Accrued unbilled revenue	255	327
Accounts receivable from affiliated companies	119	190
Fuel oil, gas in storage, materials and supplies, at average cost	270	288
Prepayments	437	113
Regulatory assets	139	121
Other current assets	92	131
TOTAL CURRENT ASSETS	2,434	3,072
INVESTMENTS	275	286
UTILITY PLANT, AT ORIGINAL COST
General	2,411	2,411
TOTAL	36,133	35,766
Less: Accumulated depreciation	7,496	7,378
Net	28,637	28,388
Construction work in progress	1,029	922
NET UTILITY PLANT	29,666	29,310
NON-UTILITY PLANT
Non-utility property, less accumulated depreciation	5	5
NET PLANT	29,671	29,315
OTHER NONCURRENT ASSETS
Regulatory assets	7,336	7,482
Other deferred charges and noncurrent assets	70	75
TOTAL OTHER NONCURRENT ASSETS	7,406	7,557
TOTAL ASSETS	39,786	40,230
CURRENT LIABILITIES
Long-term debt due within one year	650	650
Notes payable	520	1,033
Accounts payable	665	771
Accounts payable to affiliated companies	12	12
Customer deposits	341	339
Accrued taxes	39	49
Accrued taxes to affiliated companies	0	2
Accrued interest	159	118
Accrued wages	89	88
Fair value of derivative liabilities	76	50
Regulatory liabilities	97	84
Other current liabilities	461	443
TOTAL CURRENT LIABILITIES	3,109	3,639
NONCURRENT LIABILITIES
Provision for injuries and damages	186	178
Pensions and retiree benefits	2,263	2,565
Superfund and other environmental costs	667	665
Asset retirement obligations	236	234
Fair value of derivative liabilities	84	36
Deferred income taxes and unamortized investment tax credits	9,056	8,755
Regulatory liabilities	1,672	1,789
Other deferred credits and noncurrent liabilities	163	167
TOTAL NONCURRENT LIABILITIES	14,327	14,389
LONG-TERM DEBT	10,788	10,787
EQUITY
Common shareholders’ equity	11,562	11,415
TOTAL LIABILITIES AND EQUITY	39,786	40,230
Electric
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	26,616	26,358
Electric | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	25,075	24,828
Gas
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	6,967	6,858
Gas | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	6,291	6,191
Steam
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,356	2,336
Steam | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	$ 2,356	$ 2,336

Consolidated Balance Sheet (Un6

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Accounts receivable - customers, allowance for uncollectible accounts	$ 79	$ 85
Other receivables, allowance for uncollectible accounts	11	11
Non-utility property, accumulated depreciation	105	95
Intangible assets, accumulated amortization	5	4
CECONY
Accounts receivable - customers, allowance for uncollectible accounts	75	80
Other receivables, allowance for uncollectible accounts	11	11
Non-utility property, accumulated depreciation	$ 25	$ 25

Consolidated Statement of Equit

Consolidated Statement of Equity/Shareholder's Equity (Unaudited) - USD ($) $ in Millions	Total	CECONY	Common Stock	Common StockCECONY	Additional Paid-In Capital	Additional Paid-In CapitalCECONY	Retained Earnings	Retained EarningsCECONY	Repurchased Con Edison StockCECONY	Treasury Stock	Capital Stock Expense	Capital Stock ExpenseCECONY	Accumulated Other Comprehensive Income/(Loss)	Accumulated Other Comprehensive Income/(Loss)CECONY	Noncontrolling Interest
Beginning Balance at Dec. 31, 2014	$ 12,585		$ 32		$ 4,991		$ 8,691			$ (1,032)	$ (61)		$ (45)	$ (11)	$ 9
Beginning Balance at Dec. 31, 2014		$ 11,188		$ 589		$ 4,234		$ 7,399	$ (962)			$ (61)		(11)
Beginning Balance (in shares) at Dec. 31, 2014			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	370	348					370	348
Common stock dividends	(190)	(338)					(190)	(338)
Issuance of common shares for stock plans, net of repurchases					2					$ (2)
Issuance of common shares for stock plans, net of repurchases (in shares)			0							0
Other comprehensive income	5	0											5	0
Ending Balance at Mar. 31, 2015		11,198		$ 589		4,234		7,409	(962)			(61)		(11)
Ending Balance at Mar. 31, 2015	12,770		$ 32		4,993		8,871			$ (1,034)	(61)		(40)	(11)	9
Ending Balance (in shares) at Mar. 31, 2015			293,000,000	235,000,000						23,000,000
Beginning Balance at Dec. 31, 2015	13,061		$ 32		5,030		9,123			$ (1,038)	(61)		(34)	(9)	9
Beginning Balance at Dec. 31, 2015	13,052	11,415		$ 589		4,247		7,611	(962)			(61)		(9)
Beginning Balance (in shares) at Dec. 31, 2015			293,000,000	235,000,000						23,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	310	310					310	310
Common stock dividends	(197)	(186)					(197)	(186)
Issuance of common shares for stock plans, net of repurchases	28				28
Issuance of common shares for stock plans, net of repurchases (in shares)			1,000,000
Capital contribution by parent		23				23
Other comprehensive income	0	0											0	0
Noncontrolling interest	(1)														(1)
Ending Balance at Mar. 31, 2016	13,193	$ 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

General

General	3 Months Ended
	Mar. 31, 2016
General	General These combined notes accompany and form an integral part of the separate consolidated financial statements of each of the two separate registrants: Consolidated Edison, Inc. and its subsidiaries (Con Edison) and Consolidated Edison Company of New York, Inc. and its subsidiaries (CECONY). CECONY is a subsidiary of Con Edison and as such its financial condition and results of operations and cash flows, which are presented separately in the CECONY consolidated financial statements, are also consolidated, along with those of Con Edison’s other utility subsidiary, Orange and Rockland Utilities, Inc. (O&R), Con Edison Transmission, Inc. (Con Edison Transmission) (discussed below) and Con Edison’s competitive energy businesses (discussed below) in Con Edison’s consolidated financial statements. The term “Utilities” is used in these notes to refer to CECONY and O&R. As used in these notes, the term “Companies” refers to Con Edison and CECONY and, except as otherwise noted, the information in these combined notes relates to each of the Companies. However, CECONY makes no representation as to information relating to Con Edison or the subsidiaries of Con Edison other than itself. The separate interim consolidated financial statements of each of the Companies are unaudited but, in the opinion of their respective managements, reflect all adjustments (which include only normally recurring adjustments) necessary for a fair presentation of the results for the interim periods presented. The Companies’ separate interim consolidated financial statements should be read together with their separate audited financial statements (including the combined notes thereto) included in Item 8 of their combined Annual Report on Form 10-K for the year ended December 31, 2015. 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 subsidiaries, provides electric service in southeastern New York and adjacent areas of northern New Jersey and eastern Pennsylvania (see Note O) and gas service in southeastern New York and adjacent areas of eastern Pennsylvania. Con Edison has the following competitive energy businesses: Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company which sells to retail customers electricity purchased in wholesale markets (see Note O), enters into related hedging transactions and also provides energy-related products and services to retail customers; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects. In addition, Con Edison has a subsidiary, Con Edison Transmission, that invests in electric transmission facilities through its subsidiary, Consolidated Edison Transmission, LLC (CET Electric), and invests in gas pipeline and storage facilities through its subsidiary Con Edison Gas Pipeline and Storage, LLC (CET Gas).
CECONY
General	General These combined notes accompany and form an integral part of the separate consolidated financial statements of each of the two separate registrants: Consolidated Edison, Inc. and its subsidiaries (Con Edison) and Consolidated Edison Company of New York, Inc. and its subsidiaries (CECONY). CECONY is a subsidiary of Con Edison and as such its financial condition and results of operations and cash flows, which are presented separately in the CECONY consolidated financial statements, are also consolidated, along with those of Con Edison’s other utility subsidiary, Orange and Rockland Utilities, Inc. (O&R), Con Edison Transmission, Inc. (Con Edison Transmission) (discussed below) and Con Edison’s competitive energy businesses (discussed below) in Con Edison’s consolidated financial statements. The term “Utilities” is used in these notes to refer to CECONY and O&R. As used in these notes, the term “Companies” refers to Con Edison and CECONY and, except as otherwise noted, the information in these combined notes relates to each of the Companies. However, CECONY makes no representation as to information relating to Con Edison or the subsidiaries of Con Edison other than itself. The separate interim consolidated financial statements of each of the Companies are unaudited but, in the opinion of their respective managements, reflect all adjustments (which include only normally recurring adjustments) necessary for a fair presentation of the results for the interim periods presented. The Companies’ separate interim consolidated financial statements should be read together with their separate audited financial statements (including the combined notes thereto) included in Item 8 of their combined Annual Report on Form 10-K for the year ended December 31, 2015. 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 subsidiaries, provides electric service in southeastern New York and adjacent areas of northern New Jersey and eastern Pennsylvania (see Note O) and gas service in southeastern New York and adjacent areas of eastern Pennsylvania. Con Edison has the following competitive energy businesses: Consolidated Edison Solutions, Inc. (Con Edison Solutions), a company which sells to retail customers electricity purchased in wholesale markets (see Note O), enters into related hedging transactions and also provides energy-related products and services to retail customers; Consolidated Edison Energy, Inc. (Con Edison Energy), a company that provides energy-related products and services to wholesale customers; and Consolidated Edison Development, Inc. (Con Edison Development), a company that develops, owns and operates renewable and energy infrastructure projects. In addition, Con Edison has a subsidiary, Con Edison Transmission, that invests in electric transmission facilities through its subsidiary, Consolidated Edison Transmission, LLC (CET Electric), and invests in gas pipeline and storage facilities through its subsidiary Con Edison Gas Pipeline and Storage, LLC (CET Gas).

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Earnings Per Common Share For the three months ended March 31, 2016 and 2015 , basic and diluted earnings per share (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) 2016 2015 Net income $310 $370 Weighted average common shares outstanding – basic 293.7 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.1 1.0 Adjusted weighted average common shares outstanding – diluted 294.8 293.9 Net Income per common share – basic $1.05 $1.26 Net Income per common share – diluted $1.05 $1.26 The computation of diluted EPS for the three months ended March 31, 2016 and 2015 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, 2016 and 2015 , 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) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 2 — — Current period OCI, net of taxes — 5 — — Ending balance, accumulated OCI, net of taxes $(34) $(40) $(9) $(11) (a) Tax reclassified from accumulated OCI is reported in the income tax expense line item of the income statement. (b) For the portion of unrecognized pension and other postretirement benefit costs relating to the Utilities, costs are recorded into, and amortized out of, regulatory assets instead of OCI. The net actuarial losses and prior service costs recognized during the period are included in the computation of total periodic pension and other postretirement benefit cost. See Notes E and F.
CECONY
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Earnings Per Common Share For the three months ended March 31, 2016 and 2015 , basic and diluted earnings per share (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) 2016 2015 Net income $310 $370 Weighted average common shares outstanding – basic 293.7 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.1 1.0 Adjusted weighted average common shares outstanding – diluted 294.8 293.9 Net Income per common share – basic $1.05 $1.26 Net Income per common share – diluted $1.05 $1.26 The computation of diluted EPS for the three months ended March 31, 2016 and 2015 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, 2016 and 2015 , 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) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 2 — — Current period OCI, net of taxes — 5 — — Ending balance, accumulated OCI, net of taxes $(34) $(40) $(9) $(11) (a) Tax reclassified from accumulated OCI is reported in the income tax expense line item of the 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, 2016
Public Utilities, General Disclosures [Line Items]
Regulatory Matters	Regulatory Matters Rate Plans CECONY - Electric In March 2016, CECONY filed a preliminary update to its January 2016 request to the New York State Public Service Commission (NYSPSC) for an electric rate increase effective January 2017. The company decreased its requested January 2017 rate increase by $2 million to $480 million , decreased its illustrated January 2018 rate increase by $3 million to $177 million and did not change its illustrated January 2019 rate increase of $141 million . In April 2016, the Federal Energy Regulatory Commission (FERC) rejected CECONY’s challenge to FERC’s approval of substantially increased charges allocated to CECONY for transmission service provided pursuant to the open access tariff of PJM Interconnection LLC (PJM). CECONY intends to continue to challenge FERC’s approval of the increased charges. Also, in April 2016, CECONY notified PJM that CECONY will not be exercising its option to continue the service beyond April 2017. CECONY - Gas In March 2016, CECONY filed a preliminary update to its January 2016 request to the NYSPSC for a gas rate increase effective January 2017. The company increased its requested January 2017 rate increase by $5 million to $159 million , and decreased its illustrated January 2018 and 2019 rate increases by $4 million to $93 million and by $5 million to $104 million , respectively. Other Regulatory Matters In April 2016, the NYSPSC approved the September 2015 Joint Proposal among, CECONY, the NYSPSC staff and others with respect to the prudence proceeding the NYSPSC commenced in February 2009 and related matters. Pursuant to the Joint Proposal, the company is required to credit $116 million to customers and, for the period 2017 through 2044, to not seek to recover from customers an aggregate $55 million relating to return on its capital expenditures. In addition, the company’s revenues that were made subject to potential refund in this proceeding are no longer subject to refund. At March 31, 2016, the company had a $98 million regulatory liability for the remaining amount to be credited to customers related to this matter. In June 2014, the NYSPSC initiated a proceeding to investigate the practices of qualifying persons to perform plastic fusions on gas facilities. New York State regulations require gas utilities to qualify and, except in certain circumstances, annually requalify workers that perform fusion to join plastic pipe. The NYSPSC directed the New York gas utilities to provide information in this proceeding about their compliance with the qualification and requalification requirements and related matters; their procedures for compliance with all gas safety regulations; and their annual chief executive officer certifications regarding these and other procedures. CECONY’s qualification and requalification procedures had not included certain required testing to evaluate specimen fuses. In addition, CECONY and O&R had not timely requalified certain workers that had been qualified under their respective procedures to perform fusion to join plastic pipe. CECONY and O&R have requalified their workers who perform plastic pipe fusions. In May 2015, the NYSPSC, which indicated that it would address enforcement at a later date, ordered CECONY, O&R and other gas utilities to perform risk assessment and remediation plans, additional leakage surveying and reporting; CECONY to hire an independent statistician to develop a risk assessment and remediation plan; and the gas utilities to implement certain new plastic fusion requirements. In December 2015, the NYSPSC staff informed O&R that the company had satisfactorily completed its risk assessment and remediation plan. CECONY expects to submit its risk assessment and remediation plan to the NYSPSC staff in 2016. The Companies are unable to estimate the amount or range of their possible loss related to this proceeding. In November 2015, the NYSPSC ordered CECONY to show cause why the NYSPSC should not commence proceedings to penalize the company for alleged violations of gas safety regulations identified by the NYSPSC staff in its investigation of a March 2014 explosion and fire and to review the prudence of the company's conduct associated with the incident. See "Manhattan Explosion and Fire" in Note H. In December 2015, the company responded that the NYSPSC should not institute the proceedings and disputed the alleged violations. The company is unable to estimate the amount or range of its possible loss related to any such proceedings that may be instituted. Regulatory Assets and Liabilities Regulatory assets and liabilities at March 31, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,663 $3,876 $3,502 $3,697 Future income tax 2,363 2,350 2,246 2,232 Environmental remediation costs 851 904 746 800 Revenue taxes 293 253 279 240 Deferred storm costs 154 185 84 110 Deferred derivative losses 106 50 97 46 Surcharge for New York State assessment 55 44 50 40 Unamortized loss on reacquired debt 48 50 46 48 O&R property tax reconciliation 44 46 — — Pension and other postretirement benefits deferrals 41 45 11 16 Net electric deferrals 39 44 39 44 Preferred stock redemption 26 26 26 26 O&R transition bond charges 19 21 — — Workers’ compensation 16 11 16 11 Recoverable energy costs — 16 — 15 Other 212 175 194 157 Regulatory assets – noncurrent 7,930 8,096 7,336 7,482 Deferred derivative losses 143 113 131 103 Recoverable energy costs 9 19 8 18 Regulatory assets – current 152 132 139 121 Total Regulatory Assets $8,082 $8,228 $7,475 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $693 $676 $586 $570 Property tax reconciliation 259 303 259 303 Prudence proceeding 98 99 98 99 Unrecognized other postretirement costs 96 28 96 28 Base rate change deferrals 95 128 95 128 Pension and other postretirement benefit deferrals 89 76 59 46 New York State income tax rate change 71 75 69 72 Variable-rate tax-exempt debt – cost rate reconciliation 67 70 58 60 Carrying charges on repair allowance and bonus depreciation 51 49 49 48 Net unbilled revenue deferrals 44 109 44 109 Property tax refunds 33 44 33 44 Net utility plant reconciliations 30 32 30 31 Earnings sharing – electric and steam 27 80 27 80 World Trade Center settlement proceeds 15 21 15 21 Other 190 187 154 150 Regulatory liabilities – noncurrent 1,858 1,977 1,672 1,789 Revenue decoupling mechanism 69 45 69 45 Refundable energy costs 53 64 26 33 Deferred derivative gains 3 6 2 6 Regulatory liabilities – current 125 115 97 84 Total Regulatory Liabilities $1,983 $2,092 $1,769 $1,873
CECONY
Public Utilities, General Disclosures [Line Items]
Regulatory Matters	Regulatory Matters Rate Plans CECONY - Electric In March 2016, CECONY filed a preliminary update to its January 2016 request to the New York State Public Service Commission (NYSPSC) for an electric rate increase effective January 2017. The company decreased its requested January 2017 rate increase by $2 million to $480 million , decreased its illustrated January 2018 rate increase by $3 million to $177 million and did not change its illustrated January 2019 rate increase of $141 million . In April 2016, the Federal Energy Regulatory Commission (FERC) rejected CECONY’s challenge to FERC’s approval of substantially increased charges allocated to CECONY for transmission service provided pursuant to the open access tariff of PJM Interconnection LLC (PJM). CECONY intends to continue to challenge FERC’s approval of the increased charges. Also, in April 2016, CECONY notified PJM that CECONY will not be exercising its option to continue the service beyond April 2017. CECONY - Gas In March 2016, CECONY filed a preliminary update to its January 2016 request to the NYSPSC for a gas rate increase effective January 2017. The company increased its requested January 2017 rate increase by $5 million to $159 million , and decreased its illustrated January 2018 and 2019 rate increases by $4 million to $93 million and by $5 million to $104 million , respectively. Other Regulatory Matters In April 2016, the NYSPSC approved the September 2015 Joint Proposal among, CECONY, the NYSPSC staff and others with respect to the prudence proceeding the NYSPSC commenced in February 2009 and related matters. Pursuant to the Joint Proposal, the company is required to credit $116 million to customers and, for the period 2017 through 2044, to not seek to recover from customers an aggregate $55 million relating to return on its capital expenditures. In addition, the company’s revenues that were made subject to potential refund in this proceeding are no longer subject to refund. At March 31, 2016, the company had a $98 million regulatory liability for the remaining amount to be credited to customers related to this matter. In June 2014, the NYSPSC initiated a proceeding to investigate the practices of qualifying persons to perform plastic fusions on gas facilities. New York State regulations require gas utilities to qualify and, except in certain circumstances, annually requalify workers that perform fusion to join plastic pipe. The NYSPSC directed the New York gas utilities to provide information in this proceeding about their compliance with the qualification and requalification requirements and related matters; their procedures for compliance with all gas safety regulations; and their annual chief executive officer certifications regarding these and other procedures. CECONY’s qualification and requalification procedures had not included certain required testing to evaluate specimen fuses. In addition, CECONY and O&R had not timely requalified certain workers that had been qualified under their respective procedures to perform fusion to join plastic pipe. CECONY and O&R have requalified their workers who perform plastic pipe fusions. In May 2015, the NYSPSC, which indicated that it would address enforcement at a later date, ordered CECONY, O&R and other gas utilities to perform risk assessment and remediation plans, additional leakage surveying and reporting; CECONY to hire an independent statistician to develop a risk assessment and remediation plan; and the gas utilities to implement certain new plastic fusion requirements. In December 2015, the NYSPSC staff informed O&R that the company had satisfactorily completed its risk assessment and remediation plan. CECONY expects to submit its risk assessment and remediation plan to the NYSPSC staff in 2016. The Companies are unable to estimate the amount or range of their possible loss related to this proceeding. In November 2015, the NYSPSC ordered CECONY to show cause why the NYSPSC should not commence proceedings to penalize the company for alleged violations of gas safety regulations identified by the NYSPSC staff in its investigation of a March 2014 explosion and fire and to review the prudence of the company's conduct associated with the incident. See "Manhattan Explosion and Fire" in Note H. In December 2015, the company responded that the NYSPSC should not institute the proceedings and disputed the alleged violations. The company is unable to estimate the amount or range of its possible loss related to any such proceedings that may be instituted. Regulatory Assets and Liabilities Regulatory assets and liabilities at March 31, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,663 $3,876 $3,502 $3,697 Future income tax 2,363 2,350 2,246 2,232 Environmental remediation costs 851 904 746 800 Revenue taxes 293 253 279 240 Deferred storm costs 154 185 84 110 Deferred derivative losses 106 50 97 46 Surcharge for New York State assessment 55 44 50 40 Unamortized loss on reacquired debt 48 50 46 48 O&R property tax reconciliation 44 46 — — Pension and other postretirement benefits deferrals 41 45 11 16 Net electric deferrals 39 44 39 44 Preferred stock redemption 26 26 26 26 O&R transition bond charges 19 21 — — Workers’ compensation 16 11 16 11 Recoverable energy costs — 16 — 15 Other 212 175 194 157 Regulatory assets – noncurrent 7,930 8,096 7,336 7,482 Deferred derivative losses 143 113 131 103 Recoverable energy costs 9 19 8 18 Regulatory assets – current 152 132 139 121 Total Regulatory Assets $8,082 $8,228 $7,475 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $693 $676 $586 $570 Property tax reconciliation 259 303 259 303 Prudence proceeding 98 99 98 99 Unrecognized other postretirement costs 96 28 96 28 Base rate change deferrals 95 128 95 128 Pension and other postretirement benefit deferrals 89 76 59 46 New York State income tax rate change 71 75 69 72 Variable-rate tax-exempt debt – cost rate reconciliation 67 70 58 60 Carrying charges on repair allowance and bonus depreciation 51 49 49 48 Net unbilled revenue deferrals 44 109 44 109 Property tax refunds 33 44 33 44 Net utility plant reconciliations 30 32 30 31 Earnings sharing – electric and steam 27 80 27 80 World Trade Center settlement proceeds 15 21 15 21 Other 190 187 154 150 Regulatory liabilities – noncurrent 1,858 1,977 1,672 1,789 Revenue decoupling mechanism 69 45 69 45 Refundable energy costs 53 64 26 33 Deferred derivative gains 3 6 2 6 Regulatory liabilities – current 125 115 97 84 Total Regulatory Liabilities $1,983 $2,092 $1,769 $1,873

Capitalization

Capitalization	3 Months Ended
	Mar. 31, 2016
Debt Instrument [Line Items]
Capitalization	Capitalization In February 2016, a Con Edison Development subsidiary issued $218 million aggregate principal amount of 4.21 percent senior notes, due 2041 , secured by the company's Texas Solar 7 solar project. The carrying amounts and fair values of long-term debt at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $12,961 $14,710 $12,745 $13,856 CECONY $11,438 $12,995 $11,437 $12,427 Fair values of long-term debt have been estimated primarily using available market information. For Con Edison, $14,074 million and $636 million of the fair value of long-term debt at March 31, 2016 are classified as Level 2 and Level 3, respectively. For CECONY, $12,359 million and $636 million of the fair value of long-term debt at March 31, 2016 are classified as Level 2 and Level 3, respectively (see Note L). The $636 million of long-term debt classified as Level 3 is CECONY’s tax-exempt, auction-rate securities for which the market is highly illiquid and there is a lack of observable inputs.
CECONY
Debt Instrument [Line Items]
Capitalization	Capitalization In February 2016, a Con Edison Development subsidiary issued $218 million aggregate principal amount of 4.21 percent senior notes, due 2041 , secured by the company's Texas Solar 7 solar project. The carrying amounts and fair values of long-term debt at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $12,961 $14,710 $12,745 $13,856 CECONY $11,438 $12,995 $11,437 $12,427 Fair values of long-term debt have been estimated primarily using available market information. For Con Edison, $14,074 million and $636 million of the fair value of long-term debt at March 31, 2016 are classified as Level 2 and Level 3, respectively. For CECONY, $12,359 million and $636 million of the fair value of long-term debt at March 31, 2016 are classified as Level 2 and Level 3, respectively (see Note L). The $636 million of long-term debt classified as Level 3 is CECONY’s tax-exempt, auction-rate securities for which the market is highly illiquid and there is a lack of observable inputs.

Short-Term Borrowing

Short-Term Borrowing	3 Months Ended
	Mar. 31, 2016
Short-Term Borrowing	Short-Term Borrowing At March 31, 2016 , Con Edison had $1,199 million of commercial paper outstanding of which $520 million was outstanding under CECONY’s program. The weighted average interest rate at March 31, 2016 was 0.7 percent for both Con Edison and CECONY. At December 31, 2015 , Con Edison had $1,529 million of commercial paper outstanding of which $1,033 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2015 was 0.7 percent for both Con Edison and CECONY. At March 31, 2016 and December 31, 2015 , no loans were outstanding under the credit agreement (Credit Agreement) and $2 million (including $2 million for CECONY) and $15 million of letters of credit were outstanding under the Credit Agreement, respectively.
CECONY
Short-Term Borrowing	Short-Term Borrowing At March 31, 2016 , Con Edison had $1,199 million of commercial paper outstanding of which $520 million was outstanding under CECONY’s program. The weighted average interest rate at March 31, 2016 was 0.7 percent for both Con Edison and CECONY. At December 31, 2015 , Con Edison had $1,529 million of commercial paper outstanding of which $1,033 million was outstanding under CECONY’s program. The weighted average interest rate at December 31, 2015 was 0.7 percent for both Con Edison and CECONY. At March 31, 2016 and December 31, 2015 , no loans were outstanding under the credit agreement (Credit Agreement) and $2 million (including $2 million for CECONY) and $15 million of letters of credit were outstanding under the Credit Agreement, respectively.

Pension Benefits

Pension Benefits	3 Months Ended
	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Pension Benefits	Pension Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — TOTAL PERIODIC BENEFIT COST $131 $191 $121 $178 Cost capitalized (52) (68) (49) (65) Reconciliation to rate level 12 (24) 13 (24) Cost charged to operating expenses $91 $99 $85 $89 Expected Contributions Based on estimates as of March 31, 2016 , the Companies expect to make contributions to the pension plans during 2016 of $507 million (of which $469 million is to be contributed by CECONY) and $17 million related to the CECONY external trust for supplemental retirement plans. 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 2016 , the Companies contributed $153 million to the pension plans, nearly all of which was contributed by CECONY.
CECONY
Defined Benefit Plan Disclosure [Line Items]
Pension Benefits	Pension Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — TOTAL PERIODIC BENEFIT COST $131 $191 $121 $178 Cost capitalized (52) (68) (49) (65) Reconciliation to rate level 12 (24) 13 (24) Cost charged to operating expenses $91 $99 $85 $89 Expected Contributions Based on estimates as of March 31, 2016 , the Companies expect to make contributions to the pension plans during 2016 of $507 million (of which $469 million is to be contributed by CECONY) and $17 million related to the CECONY external trust for supplemental retirement plans. 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 2016 , the Companies contributed $153 million to the pension plans, nearly all of which was contributed by CECONY.

Other Postretirement Benefits

Other Postretirement Benefits	3 Months Ended
	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Other Postretirement Benefits	Other Postretirement Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic other postretirement benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (4) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(7) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 7 2 Cost charged to operating expenses $2 $4 $2 $2 Contributions Based on estimates as of March 31, 2016 , Con Edison expects to make a contribution of $6 million , nearly all of which is for CECONY, to the other postretirement benefit plans in 2016 . The Companies' policy is to fund the total periodic benefit cost of the plans to the extent tax deductible.
CECONY
Defined Benefit Plan Disclosure [Line Items]
Other Postretirement Benefits	Other Postretirement Benefits Total Periodic Benefit Cost The components of the Companies’ total periodic other postretirement benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (4) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(7) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 7 2 Cost charged to operating expenses $2 $4 $2 $2 Contributions Based on estimates as of March 31, 2016 , Con Edison expects to make a contribution of $6 million , nearly all of which is for CECONY, to the other postretirement benefit plans in 2016 . 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, 2016
Site Contingency [Line Items]
Environmental Matters	Environmental Matters Superfund Sites Hazardous substances, such as asbestos, polychlorinated biphenyls (PCBs) and coal tar, have been used or generated in the course of operations of the Utilities and their predecessors and are present at sites and in facilities and equipment they currently or previously owned, including sites at which gas was manufactured or stored. The Federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 and similar state statutes (Superfund) impose joint and several liability, regardless of fault, upon generators of hazardous substances for investigation and remediation costs (which include costs of demolition, removal, disposal, storage, replacement, containment and monitoring) and natural resource damages. Liability under these laws can be material and may be imposed for contamination from past acts, even though such past acts may have been lawful at the time they occurred. The sites at which the Utilities have been asserted to have liability under these laws, including their manufactured gas plant sites and any neighboring areas to which contamination may have migrated, are referred to herein as “Superfund Sites.” For Superfund Sites where there are other potentially responsible parties and the Utilities are not managing the site investigation and remediation, the accrued liability represents an estimate of the amount the Utilities will need to pay to investigate and, where determinable, discharge their related obligations. For Superfund Sites (including the manufactured gas plant sites) for which one of the Utilities is managing the investigation and remediation, the accrued liability represents an estimate of the company’s share of the undiscounted cost to investigate the sites and, for sites that have been investigated in whole or in part, the cost to remediate the sites, if remediation is necessary and if a reasonable estimate of such cost can be made. Remediation costs are estimated in light of the information available, applicable remediation standards and experience with similar sites. The accrued liabilities and regulatory assets related to Superfund Sites at March 31, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $678 $679 $578 $579 Other Superfund Sites 89 86 89 86 Total $767 $765 $667 $665 Regulatory assets $851 $904 $746 $800 Most of the accrued Superfund Site liability relates to sites that have been investigated, in whole or in part. However, for some of the sites, the extent and associated cost of the required remediation has not yet been determined. As investigations progress and information pertaining to the required remediation becomes available, the Utilities expect that additional liability may be accrued, the amount of which is not presently determinable but may be material. The Companies are unable to estimate the time period over which the remaining accrued liability will be incurred because, among other things, the required remediation has not been determined for some of the sites. Under their current rate plans, the Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) certain site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $3 $7 $3 $6 No insurance recoveries were received by Con Edison or CECONY for the three months ended March 31, 2016 or 2015. In 2015, Con Edison and CECONY estimated that for their manufactured gas plant sites (including CECONY’s Astoria site), the aggregate undiscounted potential liability for the investigation and remediation of coal tar and/or other environmental contaminants could range up to $2.8 billion and $2.7 billion , respectively. These estimates were based on the assumption that there is contamination at all sites, including those that have not yet been fully investigated and additional assumptions about the extent of the contamination and the type and extent of the remediation that may be required. Actual experience may be materially different. Asbestos Proceedings Suits have been brought in New York State and federal courts against the Utilities and many other defendants, wherein a large number of plaintiffs sought large amounts of compensatory and punitive damages for deaths and injuries allegedly caused by exposure to asbestos at various premises of the Utilities. The suits that have been resolved, which are many, have been resolved without any payment by the Utilities, or for amounts that were not, in the aggregate, material to them. The amounts specified in all the remaining thousands of suits total billions of dollars; however, the Utilities believe that these amounts are greatly exaggerated, based on the disposition of previous claims. At March 31, 2016 , Con Edison and CECONY had accrued their estimated aggregate undiscounted potential liabilities for these suits and additional suits that may be brought over the next 15 years as shown in the following table. The estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Trial courts have begun, and unless otherwise determined by an appellate court may continue, to apply a different standard for determining liability in asbestos suits than the standard that applied historically. As a result, the Companies currently believe that there is a reasonable possibility of an exposure to loss in excess of the liability accrued for the suits. The Companies are unable to estimate the amount or range of such loss. In addition, certain current and former employees have claimed or are claiming workers’ compensation benefits based on alleged disability from exposure to asbestos. Under its current rate plans, CECONY is permitted to defer as regulatory assets (for subsequent recovery through rates) costs incurred for its asbestos lawsuits and workers’ compensation claims. The accrued liability for asbestos suits and workers’ compensation proceedings (including those related to asbestos exposure) and the amounts deferred as regulatory assets for the Companies at March 31, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $91 $86 $86 $81 Regulatory assets – workers’ compensation $16 $11 $16 $11
CECONY
Site Contingency [Line Items]
Environmental Matters	Environmental Matters Superfund Sites Hazardous substances, such as asbestos, polychlorinated biphenyls (PCBs) and coal tar, have been used or generated in the course of operations of the Utilities and their predecessors and are present at sites and in facilities and equipment they currently or previously owned, including sites at which gas was manufactured or stored. The Federal Comprehensive Environmental Response, Compensation and Liability Act of 1980 and similar state statutes (Superfund) impose joint and several liability, regardless of fault, upon generators of hazardous substances for investigation and remediation costs (which include costs of demolition, removal, disposal, storage, replacement, containment and monitoring) and natural resource damages. Liability under these laws can be material and may be imposed for contamination from past acts, even though such past acts may have been lawful at the time they occurred. The sites at which the Utilities have been asserted to have liability under these laws, including their manufactured gas plant sites and any neighboring areas to which contamination may have migrated, are referred to herein as “Superfund Sites.” For Superfund Sites where there are other potentially responsible parties and the Utilities are not managing the site investigation and remediation, the accrued liability represents an estimate of the amount the Utilities will need to pay to investigate and, where determinable, discharge their related obligations. For Superfund Sites (including the manufactured gas plant sites) for which one of the Utilities is managing the investigation and remediation, the accrued liability represents an estimate of the company’s share of the undiscounted cost to investigate the sites and, for sites that have been investigated in whole or in part, the cost to remediate the sites, if remediation is necessary and if a reasonable estimate of such cost can be made. Remediation costs are estimated in light of the information available, applicable remediation standards and experience with similar sites. The accrued liabilities and regulatory assets related to Superfund Sites at March 31, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $678 $679 $578 $579 Other Superfund Sites 89 86 89 86 Total $767 $765 $667 $665 Regulatory assets $851 $904 $746 $800 Most of the accrued Superfund Site liability relates to sites that have been investigated, in whole or in part. However, for some of the sites, the extent and associated cost of the required remediation has not yet been determined. As investigations progress and information pertaining to the required remediation becomes available, the Utilities expect that additional liability may be accrued, the amount of which is not presently determinable but may be material. The Companies are unable to estimate the time period over which the remaining accrued liability will be incurred because, among other things, the required remediation has not been determined for some of the sites. Under their current rate plans, the Utilities are permitted to recover or defer as regulatory assets (for subsequent recovery through rates) certain site investigation and remediation costs. Environmental remediation costs incurred related to Superfund Sites for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $3 $7 $3 $6 No insurance recoveries were received by Con Edison or CECONY for the three months ended March 31, 2016 or 2015. In 2015, Con Edison and CECONY estimated that for their manufactured gas plant sites (including CECONY’s Astoria site), the aggregate undiscounted potential liability for the investigation and remediation of coal tar and/or other environmental contaminants could range up to $2.8 billion and $2.7 billion , respectively. These estimates were based on the assumption that there is contamination at all sites, including those that have not yet been fully investigated and additional assumptions about the extent of the contamination and the type and extent of the remediation that may be required. Actual experience may be materially different. Asbestos Proceedings Suits have been brought in New York State and federal courts against the Utilities and many other defendants, wherein a large number of plaintiffs sought large amounts of compensatory and punitive damages for deaths and injuries allegedly caused by exposure to asbestos at various premises of the Utilities. The suits that have been resolved, which are many, have been resolved without any payment by the Utilities, or for amounts that were not, in the aggregate, material to them. The amounts specified in all the remaining thousands of suits total billions of dollars; however, the Utilities believe that these amounts are greatly exaggerated, based on the disposition of previous claims. At March 31, 2016 , Con Edison and CECONY had accrued their estimated aggregate undiscounted potential liabilities for these suits and additional suits that may be brought over the next 15 years as shown in the following table. The estimates were based upon a combination of modeling, historical data analysis and risk factor assessment. Trial courts have begun, and unless otherwise determined by an appellate court may continue, to apply a different standard for determining liability in asbestos suits than the standard that applied historically. As a result, the Companies currently believe that there is a reasonable possibility of an exposure to loss in excess of the liability accrued for the suits. The Companies are unable to estimate the amount or range of such loss. In addition, certain current and former employees have claimed or are claiming workers’ compensation benefits based on alleged disability from exposure to asbestos. Under its current rate plans, CECONY is permitted to defer as regulatory assets (for subsequent recovery through rates) costs incurred for its asbestos lawsuits and workers’ compensation claims. The accrued liability for asbestos suits and workers’ compensation proceedings (including those related to asbestos exposure) and the amounts deferred as regulatory assets for the Companies at March 31, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $91 $86 $86 $81 Regulatory assets – workers’ compensation $16 $11 $16 $11

Other Material Contingencies

Other Material Contingencies	3 Months Ended
	Mar. 31, 2016
Guarantor Obligations [Line Items]
Other Material Contingencies	Other Material Contingencies Manhattan Steam Main Rupture In July 2007, a CECONY steam main located in midtown Manhattan ruptured. It has been reported that one person died and others were injured as a result of the incident. Several buildings in the area were damaged. Debris from the incident included dirt and mud containing asbestos. The response to the incident required the closing of several buildings and streets for various periods. Approximately eighty 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, 2016 , the company has accrued its estimated liability for the suits of $50 million and an insurance receivable in the same amount. Manhattan Explosion and Fire On March 12, 2014, two multi-use five-story tall buildings located on Park Avenue between 116 th and 117 th Street in Manhattan were destroyed by an explosion and fire. CECONY had delivered gas to the buildings through service lines from a distribution main located below ground on Park Avenue. Eight people died and more than 50 people were injured. Additional buildings were also damaged. The National Transportation Safety Board (NTSB) investigated. The parties to the investigation included the company, the City of New York, the Pipeline and Hazardous Materials Safety Administration and the NYSPSC (which also conducted an investigation). In June 2015, the NTSB issued a final report concerning the incident, its probable cause and safety recommendations. The NTSB determined that the probable cause of the incident was (1) the failure of a defective fusion joint at a service tee (which joined a plastic service line to a plastic distribution main) installed by the company that allowed gas to leak from the distribution main and migrate into a building where it ignited and (2) a breach in a City sewer line that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the distribution main, which caused it to sag and overstressed the defective fusion joint. The NTSB also made safety recommendations, including recommendations to the company that addressed its procedures for the preparation and examination of plastic fusions, training of its staff on conditions for notifications to the City’s Fire Department and extension of its gas main isolation valve installation program. Approximately 70 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 related to the incident. At March 31, 2016 , the company had not accrued a liability for the incident. Other Contingencies See “Other Regulatory Matters” in Note B and “Uncertain Tax Positions” in Note I. Guarantees Con Edison and its subsidiaries enter into various agreements providing financial or performance assurance primarily to third parties on behalf of their subsidiaries. Maximum amounts guaranteed by Con Edison totaled $2,705 million and $2,856 million at March 31, 2016 and December 31, 2015 , respectively. A summary, by type and term, of Con Edison’s total guarantees at March 31, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $791 $592 $— $1,383 Energy transactions 707 41 90 838 Renewable electric production projects 388 — 21 409 Other 75 — — 75 Total $1,961 $633 $111 $2,705 Con Edison Transmission — Con Edison has guaranteed payment by CET Electric of the contributions CET Electric agreed to make to New York Transco LLC (NY Transco). CET Electric acquired a 45.7 percent interest in NY Transco when it was formed in 2014. NY Transco’s transmission projects are expected to be developed initially by CECONY and other New York transmission owners and then transferred to NY Transco. The project transfers are subject to 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 Con Edison Transmission’s contributions, which assumes that all of the NY Transco projects proposed when NY Transco was formed receive all required regulatory approvals and are completed at 175 percent of their estimated costs and that NY Transco does not use any debt financing for the projects. Guarantee term shown is assumed as the timing of the contributions is not certain. Also included within the table above is a guarantee for $25 million from Con Edison on behalf of CET Gas in relation to a proposed gas transmission project in West Virginia and Virginia. See Note P. Energy Transactions — Con Edison guarantees payments on behalf of its competitive energy businesses in order to facilitate physical and financial transactions in electricity, gas, pipeline capacity, transportation, oil, renewable energy credits and energy services. To the extent that liabilities exist under the contracts subject to these guarantees, such liabilities are included in Con Edison’s consolidated balance sheet. 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 primarily relate to $70 million in guarantees provided by Con Edison to Travelers Insurance Company for indemnity agreements for surety bonds in connection with energy service projects and operation of solar energy facilities of Con Edison Solutions and Con Edison Development, respectively. 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. In addition to the guarantees included in the table above, in April 2016, Con Edison guaranteed (subject to a $946 million maximum amount) certain obligations of a CET Gas subsidiary under the agreement to purchase a 50 percent equity interest in a gas pipeline and storage joint venture. See Note P.
CECONY
Guarantor Obligations [Line Items]
Other Material Contingencies	Other Material Contingencies Manhattan Steam Main Rupture In July 2007, a CECONY steam main located in midtown Manhattan ruptured. It has been reported that one person died and others were injured as a result of the incident. Several buildings in the area were damaged. Debris from the incident included dirt and mud containing asbestos. The response to the incident required the closing of several buildings and streets for various periods. Approximately eighty 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, 2016 , the company has accrued its estimated liability for the suits of $50 million and an insurance receivable in the same amount. Manhattan Explosion and Fire On March 12, 2014, two multi-use five-story tall buildings located on Park Avenue between 116 th and 117 th Street in Manhattan were destroyed by an explosion and fire. CECONY had delivered gas to the buildings through service lines from a distribution main located below ground on Park Avenue. Eight people died and more than 50 people were injured. Additional buildings were also damaged. The National Transportation Safety Board (NTSB) investigated. The parties to the investigation included the company, the City of New York, the Pipeline and Hazardous Materials Safety Administration and the NYSPSC (which also conducted an investigation). In June 2015, the NTSB issued a final report concerning the incident, its probable cause and safety recommendations. The NTSB determined that the probable cause of the incident was (1) the failure of a defective fusion joint at a service tee (which joined a plastic service line to a plastic distribution main) installed by the company that allowed gas to leak from the distribution main and migrate into a building where it ignited and (2) a breach in a City sewer line that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the distribution main, which caused it to sag and overstressed the defective fusion joint. The NTSB also made safety recommendations, including recommendations to the company that addressed its procedures for the preparation and examination of plastic fusions, training of its staff on conditions for notifications to the City’s Fire Department and extension of its gas main isolation valve installation program. Approximately 70 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 related to the incident. At March 31, 2016 , the company had not accrued a liability for the incident. Other Contingencies See “Other Regulatory Matters” in Note B and “Uncertain Tax Positions” in Note I. Guarantees Con Edison and its subsidiaries enter into various agreements providing financial or performance assurance primarily to third parties on behalf of their subsidiaries. Maximum amounts guaranteed by Con Edison totaled $2,705 million and $2,856 million at March 31, 2016 and December 31, 2015 , respectively. A summary, by type and term, of Con Edison’s total guarantees at March 31, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $791 $592 $— $1,383 Energy transactions 707 41 90 838 Renewable electric production projects 388 — 21 409 Other 75 — — 75 Total $1,961 $633 $111 $2,705 Con Edison Transmission — Con Edison has guaranteed payment by CET Electric of the contributions CET Electric agreed to make to New York Transco LLC (NY Transco). CET Electric acquired a 45.7 percent interest in NY Transco when it was formed in 2014. NY Transco’s transmission projects are expected to be developed initially by CECONY and other New York transmission owners and then transferred to NY Transco. The project transfers are subject to 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 Con Edison Transmission’s contributions, which assumes that all of the NY Transco projects proposed when NY Transco was formed receive all required regulatory approvals and are completed at 175 percent of their estimated costs and that NY Transco does not use any debt financing for the projects. Guarantee term shown is assumed as the timing of the contributions is not certain. Also included within the table above is a guarantee for $25 million from Con Edison on behalf of CET Gas in relation to a proposed gas transmission project in West Virginia and Virginia. See Note P. Energy Transactions — Con Edison guarantees payments on behalf of its competitive energy businesses in order to facilitate physical and financial transactions in electricity, gas, pipeline capacity, transportation, oil, renewable energy credits and energy services. To the extent that liabilities exist under the contracts subject to these guarantees, such liabilities are included in Con Edison’s consolidated balance sheet. 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 primarily relate to $70 million in guarantees provided by Con Edison to Travelers Insurance Company for indemnity agreements for surety bonds in connection with energy service projects and operation of solar energy facilities of Con Edison Solutions and Con Edison Development, respectively. 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. In addition to the guarantees included in the table above, in April 2016, Con Edison guaranteed (subject to a $946 million maximum amount) certain obligations of a CET Gas subsidiary under the agreement to purchase a 50 percent equity interest in a gas pipeline and storage joint venture. See Note P.

Income Tax

Income Tax	3 Months Ended
	Mar. 31, 2016
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense decreased to $164 million for the three months ended March 31, 2016 from $199 million for the three months ended March 31, 2015 . Con Edison's effective tax rate for the three months ended March 31, 2016 and 2015 was 35 percent . For the three months ended March 31, 2016, Con Edison recorded income tax benefits for research and development tax credits, which were primarily offset by a decrease in tax benefits for plant-related flow through items due to a change in regulatory accounting. CECONY’s income tax expense decreased to $180 million for the three months ended March 31, 2016 from $192 million for the three months ended March 31, 2015 . CECONY's effective tax rate for the three months ended March 31, 2016 and 2015 was 37 percent and 36 percent , respectively. The increase in CECONY's effective tax rate is primarily related to a decrease in tax benefits for plant-related flow through items due to a change in regulatory accounting, partially offset by research and development tax credits. Con Edison anticipates a federal consolidated net operating loss for 2016, primarily due to bonus depreciation. Con Edison expects to carryback a portion of its 2016 net operating loss to 2014 and recover $10 million of income tax. General business tax credits that became available as a result of the net operating loss carryback to 2014, as well as the remaining 2016 net operating loss will be carried forward to future tax years. A deferred tax asset for these tax attribute carryforwards were 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, 2016 , the estimated liability for uncertain tax positions for Con Edison was $36 million ( $4 million for CECONY). Con Edison reasonably expects to resolve approximately $27 million ( $18 million , net of federal taxes) of its uncertain tax positions within the next twelve months, of which the entire amount, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $4 million ( $3 million , net of federal taxes), of which the entire amount, if recognized, would reduce CECONY’s effective tax rate. The total amount of unrecognized tax benefits, if recognized, that would reduce Con Edison’s effective tax rate is $36 million ( $24 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, 2016 , the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At March 31, 2016 and December 31, 2015 , the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.
CECONY
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense decreased to $164 million for the three months ended March 31, 2016 from $199 million for the three months ended March 31, 2015 . Con Edison's effective tax rate for the three months ended March 31, 2016 and 2015 was 35 percent . For the three months ended March 31, 2016, Con Edison recorded income tax benefits for research and development tax credits, which were primarily offset by a decrease in tax benefits for plant-related flow through items due to a change in regulatory accounting. CECONY’s income tax expense decreased to $180 million for the three months ended March 31, 2016 from $192 million for the three months ended March 31, 2015 . CECONY's effective tax rate for the three months ended March 31, 2016 and 2015 was 37 percent and 36 percent , respectively. The increase in CECONY's effective tax rate is primarily related to a decrease in tax benefits for plant-related flow through items due to a change in regulatory accounting, partially offset by research and development tax credits. Con Edison anticipates a federal consolidated net operating loss for 2016, primarily due to bonus depreciation. Con Edison expects to carryback a portion of its 2016 net operating loss to 2014 and recover $10 million of income tax. General business tax credits that became available as a result of the net operating loss carryback to 2014, as well as the remaining 2016 net operating loss will be carried forward to future tax years. A deferred tax asset for these tax attribute carryforwards were 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, 2016 , the estimated liability for uncertain tax positions for Con Edison was $36 million ( $4 million for CECONY). Con Edison reasonably expects to resolve approximately $27 million ( $18 million , net of federal taxes) of its uncertain tax positions within the next twelve months, of which the entire amount, if recognized, would reduce Con Edison’s effective tax rate. The amount related to CECONY is approximately $4 million ( $3 million , net of federal taxes), of which the entire amount, if recognized, would reduce CECONY’s effective tax rate. The total amount of unrecognized tax benefits, if recognized, that would reduce Con Edison’s effective tax rate is $36 million ( $24 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, 2016 , the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At March 31, 2016 and December 31, 2015 , the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.

Financial Information by Busine

Financial Information by Business Segment	3 Months Ended
	Mar. 31, 2016
Segment Reporting Information [Line Items]
Financial Information by Business Segment	Financial Information by Business Segment 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 (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $1,773 $1,980 $4 $4 $213 $202 $273 $279 Gas 601 655 1 1 38 35 253 241 Steam 258 375 22 22 21 20 114 164 Consolidation adjustments — — (27) (27) — — — — Total CECONY $2,632 $3,010 $— $— $272 $257 $640 $684 O&R Electric $140 $156 $— $— $12 $12 $18 $18 Gas 75 77 — — 5 5 35 27 Total O&R $215 $233 $— $— $17 $17 $53 $45 Competitive energy businesses $310 $374 $6 $(3) $9 $5 $(51) $(3) Other (a) (1) (1) (6) 3 (1) — — — Total Con Edison $3,156 $3,616 $— $— $297 $279 $642 $726 (a) Parent company, consolidation adjustments and Con Edison Transmission. Other does not represent a business segment.
CECONY
Segment Reporting Information [Line Items]
Financial Information by Business Segment	Financial Information by Business Segment 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 (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $1,773 $1,980 $4 $4 $213 $202 $273 $279 Gas 601 655 1 1 38 35 253 241 Steam 258 375 22 22 21 20 114 164 Consolidation adjustments — — (27) (27) — — — — Total CECONY $2,632 $3,010 $— $— $272 $257 $640 $684 O&R Electric $140 $156 $— $— $12 $12 $18 $18 Gas 75 77 — — 5 5 35 27 Total O&R $215 $233 $— $— $17 $17 $53 $45 Competitive energy businesses $310 $374 $6 $(3) $9 $5 $(51) $(3) Other (a) (1) (1) (6) 3 (1) — — — Total Con Edison $3,156 $3,616 $— $— $297 $279 $642 $726 (a) Parent company, consolidation adjustments and Con Edison Transmission. Other does not represent a business segment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2016
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Con Edison’s subsidiaries hedge market price fluctuations associated with physical purchases and sales of electricity, natural gas, steam and, to a lesser extent, refined fuels by using derivative instruments including futures, forwards, basis swaps, options, transmission congestion contracts and financial transmission rights contracts. Derivatives are recognized on the consolidated balance sheet at fair value (see Note L), unless an exception is available under the accounting rules for derivatives and hedging. Qualifying derivative contracts that have been designated as normal purchases or normal sales contracts are not reported at fair value under the accounting rules. The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Balance Sheet Location Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Con Edison Fair value of derivative assets Current $42 $(34) $8 (b) $59 $(41) $18 (b) Current - assets held for sale (c) 55 (54) 1 51 (50) 1 Noncurrent 25 (24) 1 57 (54) 3 Noncurrent - assets held for sale (c) 13 (13) — 15 (15) — Total fair value of derivative assets $135 $(125) $10 $182 $(160) $22 Fair value of derivative liabilities Current $(169) $79 $(90) $(144) $78 $(66) Current - liabilities held for sale (c) (152) 54 (98) (115) 50 (65) Noncurrent (128) 36 (92) (102) 63 (39) Noncurrent - liabilities held for sale (c) (54) 13 (41) (28) 15 (13) Total fair value of derivative liabilities $(503) $182 $(321) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(368) $57 $(311) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $25 $(23) $2 (b) $40 $(32) $8 (b) Noncurrent 15 (15) — 48 (47) 1 Total fair value of derivative assets $40 $(38) $2 $88 $(79) $9 Fair value of derivative liabilities Current $(145) $69 $(76) $(121) $71 $(50) Noncurrent (112) 28 (84) (92) 56 (36) Total fair value of derivative liabilities $(257) $97 $(160) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(217) $59 $(158) (b) $(125) $48 $(77) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At March 31, 2016 and December 31, 2015 , margin deposits for Con Edison ( $18 million and $26 million , respectively) and CECONY ( $18 million and $26 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet (see Note O). The Utilities generally recover their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state utility regulators. In accordance with the accounting rules for regulated operations, the Utilities record a regulatory asset or liability to defer recognition of unrealized gains and losses on their electric and gas derivatives. As gains and losses are realized in future periods, they will be recognized as purchased power, gas and fuel costs in the Companies’ consolidated income statements. Con Edison’s competitive energy businesses record realized and unrealized gains and losses on their derivative contracts in purchased power, gas purchased for resale and non-utility revenue in the reporting period in which they occur. Management believes that these derivative instruments represent economic hedges that mitigate exposure to fluctuations in commodity prices. The following table presents the realized and unrealized gains or losses on commodity derivatives that have been deferred or recognized in earnings for the three months ended March 31, 2016 and 2015 : For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(4) $3 $(4) $3 Noncurrent Deferred derivative gains — — (1) — Total deferred gains/(losses) $(4) $3 $(5) $3 Current Deferred derivative losses $(30) $43 $(28) $41 Current Recoverable energy costs (73) — (66) (2) Noncurrent Deferred derivative losses (56) (19) (51) (16) Total deferred gains/(losses) $(159) $24 $(145) $23 Net deferred gains/(losses) $(163) $27 $(150) $26 Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(114) (a) $21 (b) $— $— Gas purchased for resale (10) (42) — — Non-utility revenue 11 (a) 42 (b) — — Total pre-tax gain/(loss) recognized in income $(113) $21 $— $— (a) 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). (b) For the three months ended March 31, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $4 million loss) and purchased power expense ( $12 million gain). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at March 31, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison (c) 34,331,960 26,658 43,472,324 5,376,000 CECONY 17,173,925 12,000 40,280,000 5,376,000 (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. (c) Includes 15,495,945 MWh for electric energy, 11,817 MW for capacity and 552,073 Dt for natural gas derivative transactions that are held for sale. The Companies are exposed to credit risk related to transactions entered into primarily for the various energy supply and hedging activities by the Utilities and the competitive energy businesses. Credit risk relates to the loss that may result from a counterparty’s nonperformance. The Companies use credit policies to manage this risk, including an established credit approval process, monitoring of counterparty limits, netting provisions within agreements, collateral or prepayment arrangements, credit insurance and credit default swaps. The Companies measure credit risk exposure as the replacement cost for open energy commodity and derivative positions plus amounts owed from counterparties for settled transactions. The replacement cost of open positions represents unrealized gains, net of any unrealized losses where the Companies have a legally enforceable right to offset. At March 31, 2016 , Con Edison and CECONY had $209 million and $17 million of credit exposure in connection with energy supply and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $112 million with commodity exchange brokers, $63 million with independent system operators, $27 million with investment-grade counterparties and $7 million with non-investment grade/non-rated counterparties. CECONY’s net credit exposure was with commodity exchange brokers. The collateral requirements associated with, and settlement of, derivative transactions are included in net cash flows from operating activities in the Companies’ consolidated statement of cash flows. Most derivative instrument contracts contain provisions that may require a party to provide collateral on its derivative instruments that are in a net liability position. The amount of collateral to be provided will depend on the fair value of the derivative instruments and the party’s credit ratings. The following table presents the aggregate fair value of the Companies’ derivative instruments with credit-risk-related contingent features that are in a net liability position, the collateral posted for such positions and the additional collateral that would have been required to be posted had the lowest applicable credit rating been reduced one level and to below investment grade at March 31, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $187 $152 Collateral posted 45 44 Additional collateral (b) (downgrade one level from current ratings) 30 20 Additional collateral (b) (downgrade to below investment grade from current ratings) 192 (c) 148 (c) (a) Non-derivative transactions for the purchase and sale of electricity and gas and qualifying derivative instruments, which have been designated as normal purchases or normal sales, are excluded from the table. These transactions primarily include purchases of electricity from independent system operators. In the event the Utilities and the competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $7 million at March 31, 2016 . For certain other such non-derivative transactions, the Companies could be required to post collateral under certain circumstances, including in the event counterparties had reasonable grounds for insecurity. (b) The Companies measure the collateral requirements by taking into consideration the fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liabilities position plus amounts owed to counterparties for settled transactions and amounts required by counterparties for minimum financial security. The fair value amounts represent unrealized losses, net of any unrealized gains where the Companies have a legally enforceable right to offset. (c) Derivative instruments that are net assets have been excluded from the table. At March 31, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $16 million .
CECONY
Derivative [Line Items]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Con Edison’s subsidiaries hedge market price fluctuations associated with physical purchases and sales of electricity, natural gas, steam and, to a lesser extent, refined fuels by using derivative instruments including futures, forwards, basis swaps, options, transmission congestion contracts and financial transmission rights contracts. Derivatives are recognized on the consolidated balance sheet at fair value (see Note L), unless an exception is available under the accounting rules for derivatives and hedging. Qualifying derivative contracts that have been designated as normal purchases or normal sales contracts are not reported at fair value under the accounting rules. The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Balance Sheet Location Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Con Edison Fair value of derivative assets Current $42 $(34) $8 (b) $59 $(41) $18 (b) Current - assets held for sale (c) 55 (54) 1 51 (50) 1 Noncurrent 25 (24) 1 57 (54) 3 Noncurrent - assets held for sale (c) 13 (13) — 15 (15) — Total fair value of derivative assets $135 $(125) $10 $182 $(160) $22 Fair value of derivative liabilities Current $(169) $79 $(90) $(144) $78 $(66) Current - liabilities held for sale (c) (152) 54 (98) (115) 50 (65) Noncurrent (128) 36 (92) (102) 63 (39) Noncurrent - liabilities held for sale (c) (54) 13 (41) (28) 15 (13) Total fair value of derivative liabilities $(503) $182 $(321) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(368) $57 $(311) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $25 $(23) $2 (b) $40 $(32) $8 (b) Noncurrent 15 (15) — 48 (47) 1 Total fair value of derivative assets $40 $(38) $2 $88 $(79) $9 Fair value of derivative liabilities Current $(145) $69 $(76) $(121) $71 $(50) Noncurrent (112) 28 (84) (92) 56 (36) Total fair value of derivative liabilities $(257) $97 $(160) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(217) $59 $(158) (b) $(125) $48 $(77) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At March 31, 2016 and December 31, 2015 , margin deposits for Con Edison ( $18 million and $26 million , respectively) and CECONY ( $18 million and $26 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet (see Note O). The Utilities generally recover their prudently incurred fuel, purchased power and gas costs, including hedging gains and losses, in accordance with rate provisions approved by the applicable state utility regulators. In accordance with the accounting rules for regulated operations, the Utilities record a regulatory asset or liability to defer recognition of unrealized gains and losses on their electric and gas derivatives. As gains and losses are realized in future periods, they will be recognized as purchased power, gas and fuel costs in the Companies’ consolidated income statements. Con Edison’s competitive energy businesses record realized and unrealized gains and losses on their derivative contracts in purchased power, gas purchased for resale and non-utility revenue in the reporting period in which they occur. Management believes that these derivative instruments represent economic hedges that mitigate exposure to fluctuations in commodity prices. The following table presents the realized and unrealized gains or losses on commodity derivatives that have been deferred or recognized in earnings for the three months ended March 31, 2016 and 2015 : For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(4) $3 $(4) $3 Noncurrent Deferred derivative gains — — (1) — Total deferred gains/(losses) $(4) $3 $(5) $3 Current Deferred derivative losses $(30) $43 $(28) $41 Current Recoverable energy costs (73) — (66) (2) Noncurrent Deferred derivative losses (56) (19) (51) (16) Total deferred gains/(losses) $(159) $24 $(145) $23 Net deferred gains/(losses) $(163) $27 $(150) $26 Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(114) (a) $21 (b) $— $— Gas purchased for resale (10) (42) — — Non-utility revenue 11 (a) 42 (b) — — Total pre-tax gain/(loss) recognized in income $(113) $21 $— $— (a) 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). (b) For the three months ended March 31, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $4 million loss) and purchased power expense ( $12 million gain). The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at March 31, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison (c) 34,331,960 26,658 43,472,324 5,376,000 CECONY 17,173,925 12,000 40,280,000 5,376,000 (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. (c) Includes 15,495,945 MWh for electric energy, 11,817 MW for capacity and 552,073 Dt for natural gas derivative transactions that are held for sale. The Companies are exposed to credit risk related to transactions entered into primarily for the various energy supply and hedging activities by the Utilities and the competitive energy businesses. Credit risk relates to the loss that may result from a counterparty’s nonperformance. The Companies use credit policies to manage this risk, including an established credit approval process, monitoring of counterparty limits, netting provisions within agreements, collateral or prepayment arrangements, credit insurance and credit default swaps. The Companies measure credit risk exposure as the replacement cost for open energy commodity and derivative positions plus amounts owed from counterparties for settled transactions. The replacement cost of open positions represents unrealized gains, net of any unrealized losses where the Companies have a legally enforceable right to offset. At March 31, 2016 , Con Edison and CECONY had $209 million and $17 million of credit exposure in connection with energy supply and hedging activities, net of collateral, respectively. Con Edison’s net credit exposure consisted of $112 million with commodity exchange brokers, $63 million with independent system operators, $27 million with investment-grade counterparties and $7 million with non-investment grade/non-rated counterparties. CECONY’s net credit exposure was with commodity exchange brokers. The collateral requirements associated with, and settlement of, derivative transactions are included in net cash flows from operating activities in the Companies’ consolidated statement of cash flows. Most derivative instrument contracts contain provisions that may require a party to provide collateral on its derivative instruments that are in a net liability position. The amount of collateral to be provided will depend on the fair value of the derivative instruments and the party’s credit ratings. The following table presents the aggregate fair value of the Companies’ derivative instruments with credit-risk-related contingent features that are in a net liability position, the collateral posted for such positions and the additional collateral that would have been required to be posted had the lowest applicable credit rating been reduced one level and to below investment grade at March 31, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $187 $152 Collateral posted 45 44 Additional collateral (b) (downgrade one level from current ratings) 30 20 Additional collateral (b) (downgrade to below investment grade from current ratings) 192 (c) 148 (c) (a) Non-derivative transactions for the purchase and sale of electricity and gas and qualifying derivative instruments, which have been designated as normal purchases or normal sales, are excluded from the table. These transactions primarily include purchases of electricity from independent system operators. In the event the Utilities and the competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $7 million at March 31, 2016 . For certain other such non-derivative transactions, the Companies could be required to post collateral under certain circumstances, including in the event counterparties had reasonable grounds for insecurity. (b) The Companies measure the collateral requirements by taking into consideration the fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liabilities position plus amounts owed to counterparties for settled transactions and amounts required by counterparties for minimum financial security. The fair value amounts represent unrealized losses, net of any unrealized gains where the Companies have a legally enforceable right to offset. (c) Derivative instruments that are net assets have been excluded from the table. At March 31, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $16 million .

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements	Fair Value Measurements The accounting rules for fair value measurements and disclosures define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable firm inputs. The Companies often make certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. The Companies use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting rules for fair value measurements and disclosures established a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The rules require that assets and liabilities be classified in their entirety based on the level of input that is significant to the fair value measurement. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and their placement within the fair value hierarchy. The Companies classify fair value balances based on the fair value hierarchy defined by the accounting rules for fair value measurements and disclosures as follows: • Level 1 – Consists of assets or liabilities whose value is based on unadjusted quoted prices in active markets at the measurement date. An active market is one in which transactions for assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes contracts traded on active exchange markets valued using unadjusted prices quoted directly from the exchange. • Level 2 – Consists of assets or liabilities valued using industry standard models and based on prices, other than quoted prices within Level 1, that are either directly or indirectly observable as of the measurement date. The industry standard models consider observable assumptions including time value, volatility factors and current market and contractual prices for the underlying commodities, in addition to other economic measures. This category includes contracts traded on active exchanges or in over-the-counter markets priced with industry standard models. • Level 3 – Consists of assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost benefit constraints. This category includes contracts priced using models that are internally developed and contracts placed in illiquid markets. It also includes contracts that expire after the period of time for which quoted prices are available and internal models are used to determine a significant portion of the value. Assets and liabilities measured at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 are summarized below. 2016 2015 (Millions of Dollars) Level 1 Level 2 Level 3 Netting Adjustment (e) Total Level 1 Level 2 Level 3 Netting Adjustment (e) Total Con Edison Derivative assets: Commodity (a)(b)(c) $— $19 $6 $2 $27 $2 $25 $13 $7 $47 Commodity held for sale (f) — 51 2 (52) 1 — 63 1 (63) 1 Other (a)(b)(d) 174 113 — — 287 185 112 — — 297 Total assets $174 $183 $8 $(50) $315 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $12 $241 $2 $(73) $182 $16 $153 $1 $(65) $105 Commodity held for sale (f) 1 180 10 (52) 139 1 133 7 (63) 78 Total liabilities $13 $421 $12 $(125) $321 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $— $2 $2 $16 $20 $1 $9 $8 $17 $35 Other (a)(b)(d) 160 106 — — 266 171 105 — — 276 Total assets $160 $108 $2 $16 $286 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $12 $209 $— $(61) $160 $14 $129 $— $(57) $86 (a) The Companies’ policy is to review the fair value hierarchy and recognize transfers into and transfers out of the levels at the end of each reporting period. There were no transfers between levels 1, 2 and 3 for the three months ended March 31, 2016 and for the year ended December 31, 2015 . (b) Level 2 assets and liabilities include investments held in the deferred compensation plan and/or non-qualified retirement plans, exchange-traded contracts where there is insufficient market liquidity to warrant inclusion in Level 1, certain over-the-counter derivative instruments for electricity, refined products and natural gas. Derivative instruments classified as Level 2 are valued using industry standard models that incorporate corroborated observable inputs; such as pricing services or prices from similar instruments that trade in liquid markets, time value and volatility factors. (c) The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At March 31, 2016 and December 31, 2015 , the Companies determined that nonperformance risk would have no material impact on their financial position or results of operations. (d) Other assets are comprised of assets such as life insurance contracts within the deferred compensation plan and non-qualified retirement plans. (e) Amounts represent the impact of legally-enforceable master netting agreements that allow the Companies to net gain and loss positions and cash collateral held or placed with the same counterparties. (f) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet (see Note O). The employees in the Companies’ risk management group develop and maintain the Companies’ valuation policies and procedures for, and verify pricing and fair value valuation of, commodity derivatives. Under the Companies’ policies and procedures, multiple independent sources of information are obtained for forward price curves used to value commodity derivatives. Fair value and changes in fair value of commodity derivatives are reported on a monthly basis to the Companies’ risk committees, comprised of officers and employees of the Companies that oversee energy hedging at the Utilities and the competitive energy businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at March 31, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(7) Discounted Cash Flow Forward energy prices (a) $15.32-$74.99 per MWh Discounted Cash Flow Forward capacity prices (a) $0.58-$8.10 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 3 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(5.10)-$2.25 per MWh Total Con Edison—Commodity $(4) CECONY—Commodity Transmission Congestion Contracts $2 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% (a) Generally, increases/(decreases) in this input in isolation would result in a higher/(lower) fair value measurement. (b) Generally, increases/(decreases) in this input in isolation would result in a lower/(higher) fair value measurement. The table listed below provides a reconciliation of the beginning and ending net balances for assets and liabilities measured at fair value as of March 31, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (7) (10) (1) (2) Included in regulatory assets and liabilities (3) — (4) — Purchases — 3 — 2 Settlements — (2) (1) (1) Ending balance as of March 31, $(4) $11 $2 $12 For the Utilities, realized gains and losses on Level 3 commodity derivative assets and liabilities are reported as part of purchased power, gas and fuel costs. The Utilities generally recover these costs in accordance with rate provisions approved by the applicable state public utilities regulators. Unrealized gains and losses for commodity derivatives are generally deferred on the consolidated balance sheet in accordance with the accounting rules for regulated operations. For the competitive energy businesses, realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues (immaterial for both periods) and purchased power costs ( $6 million loss and $8 million loss ) on the consolidated income statement for the three months ended March 31, 2016 and 2015 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at March 31, 2016 and 2015 is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $4 million loss and $5 million loss ) on the consolidated income statement for the three months ended March 31, 2016 and 2015 , respectively.
CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements	Fair Value Measurements The accounting rules for fair value measurements and disclosures define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable firm inputs. The Companies often make certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. The Companies use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. The accounting rules for fair value measurements and disclosures established a fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The rules require that assets and liabilities be classified in their entirety based on the level of input that is significant to the fair value measurement. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and their placement within the fair value hierarchy. The Companies classify fair value balances based on the fair value hierarchy defined by the accounting rules for fair value measurements and disclosures as follows: • Level 1 – Consists of assets or liabilities whose value is based on unadjusted quoted prices in active markets at the measurement date. An active market is one in which transactions for assets or liabilities occur with sufficient frequency and volume to provide pricing information on an ongoing basis. This category includes contracts traded on active exchange markets valued using unadjusted prices quoted directly from the exchange. • Level 2 – Consists of assets or liabilities valued using industry standard models and based on prices, other than quoted prices within Level 1, that are either directly or indirectly observable as of the measurement date. The industry standard models consider observable assumptions including time value, volatility factors and current market and contractual prices for the underlying commodities, in addition to other economic measures. This category includes contracts traded on active exchanges or in over-the-counter markets priced with industry standard models. • Level 3 – Consists of assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost benefit constraints. This category includes contracts priced using models that are internally developed and contracts placed in illiquid markets. It also includes contracts that expire after the period of time for which quoted prices are available and internal models are used to determine a significant portion of the value. Assets and liabilities measured at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 are summarized below. 2016 2015 (Millions of Dollars) Level 1 Level 2 Level 3 Netting Adjustment (e) Total Level 1 Level 2 Level 3 Netting Adjustment (e) Total Con Edison Derivative assets: Commodity (a)(b)(c) $— $19 $6 $2 $27 $2 $25 $13 $7 $47 Commodity held for sale (f) — 51 2 (52) 1 — 63 1 (63) 1 Other (a)(b)(d) 174 113 — — 287 185 112 — — 297 Total assets $174 $183 $8 $(50) $315 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $12 $241 $2 $(73) $182 $16 $153 $1 $(65) $105 Commodity held for sale (f) 1 180 10 (52) 139 1 133 7 (63) 78 Total liabilities $13 $421 $12 $(125) $321 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $— $2 $2 $16 $20 $1 $9 $8 $17 $35 Other (a)(b)(d) 160 106 — — 266 171 105 — — 276 Total assets $160 $108 $2 $16 $286 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $12 $209 $— $(61) $160 $14 $129 $— $(57) $86 (a) The Companies’ policy is to review the fair value hierarchy and recognize transfers into and transfers out of the levels at the end of each reporting period. There were no transfers between levels 1, 2 and 3 for the three months ended March 31, 2016 and for the year ended December 31, 2015 . (b) Level 2 assets and liabilities include investments held in the deferred compensation plan and/or non-qualified retirement plans, exchange-traded contracts where there is insufficient market liquidity to warrant inclusion in Level 1, certain over-the-counter derivative instruments for electricity, refined products and natural gas. Derivative instruments classified as Level 2 are valued using industry standard models that incorporate corroborated observable inputs; such as pricing services or prices from similar instruments that trade in liquid markets, time value and volatility factors. (c) The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At March 31, 2016 and December 31, 2015 , the Companies determined that nonperformance risk would have no material impact on their financial position or results of operations. (d) Other assets are comprised of assets such as life insurance contracts within the deferred compensation plan and non-qualified retirement plans. (e) Amounts represent the impact of legally-enforceable master netting agreements that allow the Companies to net gain and loss positions and cash collateral held or placed with the same counterparties. (f) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet (see Note O). The employees in the Companies’ risk management group develop and maintain the Companies’ valuation policies and procedures for, and verify pricing and fair value valuation of, commodity derivatives. Under the Companies’ policies and procedures, multiple independent sources of information are obtained for forward price curves used to value commodity derivatives. Fair value and changes in fair value of commodity derivatives are reported on a monthly basis to the Companies’ risk committees, comprised of officers and employees of the Companies that oversee energy hedging at the Utilities and the competitive energy businesses. The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at March 31, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(7) Discounted Cash Flow Forward energy prices (a) $15.32-$74.99 per MWh Discounted Cash Flow Forward capacity prices (a) $0.58-$8.10 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 3 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(5.10)-$2.25 per MWh Total Con Edison—Commodity $(4) CECONY—Commodity Transmission Congestion Contracts $2 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% (a) Generally, increases/(decreases) in this input in isolation would result in a higher/(lower) fair value measurement. (b) Generally, increases/(decreases) in this input in isolation would result in a lower/(higher) fair value measurement. The table listed below provides a reconciliation of the beginning and ending net balances for assets and liabilities measured at fair value as of March 31, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (7) (10) (1) (2) Included in regulatory assets and liabilities (3) — (4) — Purchases — 3 — 2 Settlements — (2) (1) (1) Ending balance as of March 31, $(4) $11 $2 $12 For the Utilities, realized gains and losses on Level 3 commodity derivative assets and liabilities are reported as part of purchased power, gas and fuel costs. The Utilities generally recover these costs in accordance with rate provisions approved by the applicable state public utilities regulators. Unrealized gains and losses for commodity derivatives are generally deferred on the consolidated balance sheet in accordance with the accounting rules for regulated operations. For the competitive energy businesses, realized and unrealized gains and losses on Level 3 commodity derivative assets and liabilities are reported in non-utility revenues (immaterial for both periods) and purchased power costs ( $6 million loss and $8 million loss ) on the consolidated income statement for the three months ended March 31, 2016 and 2015 , respectively. The change in fair value relating to Level 3 commodity derivative assets and liabilities held at March 31, 2016 and 2015 is included in non-utility revenues ( immaterial for both periods) and purchased power costs ( $4 million loss and $5 million loss ) on the consolidated income statement for the three months ended March 31, 2016 and 2015 , respectively.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2016
Schedule of Equity Method Investments [Line Items]
Variable Interest Entities	Variable Interest Entities Con Edison enters into arrangements including leases, partnerships and electricity purchase agreements, with various entities. As a result of these arrangements, Con Edison retains or may retain a variable interest in these entities. CECONY has a variable interest in a non-consolidated variable interest entity (VIE), Astoria Energy, LLC (Astoria Energy), with which CECONY has entered into a long-term electricity purchase agreement. CECONY is not the primary beneficiary of this VIE because CECONY does not have the power to direct activities that it deems most significant to the economic performance of Astoria Energy. In particular, CECONY has not invested in, or guaranteed the indebtedness of, Astoria Energy and CECONY does not operate or maintain Astoria Energy’s generating facilities. CECONY also has long-term electricity purchase agreements with the following two potential VIEs: Cogen Technologies Linden Venture, LP, and Brooklyn Navy Yard Cogeneration Partners, LP. In 2015 , requests were made of these two counterparties for information necessary to determine whether the entity was a VIE and whether CECONY is the primary beneficiary; however, the information was not made available. The payments for these contracts constitute CECONY’s maximum exposure to loss with respect to the potential VIEs. The following table summarizes the VIEs in which Con Edison Development has entered into as of March 31, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $183 Panoche Valley 124 20 2015 California 133 Mesquite Solar 1 83 20 2013 Arizona 99 Copper Mountain Solar 2 75 25 2013 Nevada 82 California Solar 55 25 2012 California 65 Broken Bow II 38 25 2014 Nebraska 54 Texas Solar 4 32 25 2014 Texas 15 Pilesgrove 9 n/a (d) 2010 New Jersey 26 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. Con Edison is the primary beneficiary since the power to direct the activities that most significantly impact the economics of Texas Solar 4 is held by Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the investment on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) Pilesgrove has 3 - 4 year Solar Renewable Energy Credit hedges in place.
CECONY
Schedule of Equity Method Investments [Line Items]
Variable Interest Entities	Variable Interest Entities Con Edison enters into arrangements including leases, partnerships and electricity purchase agreements, with various entities. As a result of these arrangements, Con Edison retains or may retain a variable interest in these entities. CECONY has a variable interest in a non-consolidated variable interest entity (VIE), Astoria Energy, LLC (Astoria Energy), with which CECONY has entered into a long-term electricity purchase agreement. CECONY is not the primary beneficiary of this VIE because CECONY does not have the power to direct activities that it deems most significant to the economic performance of Astoria Energy. In particular, CECONY has not invested in, or guaranteed the indebtedness of, Astoria Energy and CECONY does not operate or maintain Astoria Energy’s generating facilities. CECONY also has long-term electricity purchase agreements with the following two potential VIEs: Cogen Technologies Linden Venture, LP, and Brooklyn Navy Yard Cogeneration Partners, LP. In 2015 , requests were made of these two counterparties for information necessary to determine whether the entity was a VIE and whether CECONY is the primary beneficiary; however, the information was not made available. The payments for these contracts constitute CECONY’s maximum exposure to loss with respect to the potential VIEs. The following table summarizes the VIEs in which Con Edison Development has entered into as of March 31, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $183 Panoche Valley 124 20 2015 California 133 Mesquite Solar 1 83 20 2013 Arizona 99 Copper Mountain Solar 2 75 25 2013 Nevada 82 California Solar 55 25 2012 California 65 Broken Bow II 38 25 2014 Nebraska 54 Texas Solar 4 32 25 2014 Texas 15 Pilesgrove 9 n/a (d) 2010 New Jersey 26 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. Con Edison is the primary beneficiary since the power to direct the activities that most significantly impact the economics of Texas Solar 4 is held by Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the investment on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) Pilesgrove has 3 - 4 year Solar Renewable Energy Credit hedges in place.

New Financial Accounting Standa

New Financial Accounting Standards	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the FASB and the International Accounting Standards Board (IASB) jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity.
CECONY
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the FASB and the International Accounting Standards Board (IASB) jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity.

Assets Held For Sale

Assets Held For Sale	3 Months Ended
	Mar. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Assets Held For Sale	Assets Held For Sale In June 2015, upon evaluating strategic alternatives, Con Edison initiated a plan to actively market and sell the retail electric supply business of its competitive energy businesses. The company expects the sale to close within the next twelve months. The company classified as held for sale the related assets and liabilities and ceased recording depreciation expense on these assets. There was no impairment of the assets held for sale, as the estimated fair value less costs to sell exceeded the carrying amount. In October 2015, upon evaluating strategic alternatives, O&R entered into an agreement to sell Pike County Light & Power Company (Pike) to Corning Natural Gas Holding Corporation for $16 million , including estimated working capital adjustments. The closing of the sale, which the company expects to occur in 2016, is subject to certain regulatory approvals by the FERC and Pennsylvania Public Utility Commission. In 2015, the company classified the related electric and gas assets and liabilities as held for sale and ceased recording depreciation expense on these assets. At September 30, 2015, O&R recorded an impairment charge of $5 million ( $3 million net of taxes), representing the difference between the carrying amount of Pike’s assets and the estimated sales proceeds. The impairment is reflected in the amount included in assets held for sale on the company's consolidated balance sheet at March 31, 2016 . At March 31, 2016 , the carrying amounts of the assets and liabilities designated as held for sale were as follows: (Millions of Dollars) Retail Electric Supply Business Pike Total Cash and temporary cash investments $— $7 $7 Accounts receivable less allowance for uncollectible accounts of $2 67 — 67 Accrued unbilled revenue 67 1 68 Other assets 2 1 3 Total current assets 136 9 145 Utility plant, less accumulated depreciation of $6 — 14 14 Non-utility property, less accumulated depreciation of $13 3 — 3 Non-utility property construction work in progress 1 — 1 Regulatory assets — 3 3 Total assets held for sale $140 $26 $166 Fair value of derivative liabilities $98 $— $98 Accounts payable 3 — 3 Other 3 2 5 Total current liabilities 104 2 106 Fair value of derivative liabilities 41 — 41 Long-term debt — 3 3 Total liabilities held for sale $145 $5 $150

Acquisitions, Investments and D

Acquisitions, Investments and Dispositions	3 Months Ended
	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Acquisitions, Investments and Dispositions	Acquisitions, Investments and Dispositions Texas Solar 7 In January 2016, Con Edison Development acquired a company that is the owner of a 106 MW (AC) solar electric production project in Texas (Texas Solar 7) for $227 million ; $218 million was recorded as non-utility construction work in progress and the remaining $9 million was recorded as other receivables. The total cost of this project is expected to be approximately $375 million . The project will be financed, in part, by debt secured by the project (see Note C). Electricity generated by this project is to be purchased by the City of San Antonio pursuant to a long-term power purchase agreement. The project is targeted to be fully in-service during 2016. Mountain Valley Pipeline In January 2016, CET Gas acquired a 12.5 percent ownership interest in Mountain Valley Pipeline, LLC (MVP), a company developing a proposed gas transmission project in West Virginia and Virginia. The company's initial contribution to MVP was $18 million . MVP has indicated that the estimated total project cost is $3,000 million to $3,500 million . Con Edison is accounting for its equity interest in MVP as an equity method investment. Subject to FERC approval, MVP is targeting to be fully in-service during the fourth quarter of 2018. Stagecoach Gas Services In April 2016, a CET Gas subsidiary agreed with a subsidiary of Crestwood Equity Partners LP (Crestwood) to form a joint venture to own, operate and further develop existing natural gas pipeline and storage businesses located in northern Pennsylvania and southern New York. Subject to customary closing conditions, Crestwood will contribute these businesses to a new entity, Stagecoach Gas Services LLC (Stagecoach), and the CET Gas subsidiary will purchase a 50 percent equity interest in Stagecoach for $975 million (subject to closing adjustments). Con Edison, which has guaranteed (subject to a $946 million maximum amount) certain obligations of the CET Gas subsidiary under the agreement, will account for its equity interest in Stagecoach as an equity method investment. The transaction is expected to be substantially completed in the second quarter of 2016. NY Transco In January 2016, CECONY entered into an agreement to transfer certain electric transmission projects to NY Transco, a company in which CET Electric has a 45.7 percent ownership interest. In April 2016, the NYSPSC authorized CECONY, subject to certain conditions, to transfer the projects to NY Transco for a purchase price limited to CECONY's actual costs associated with the projects and a $7.6 million payment for the lease of certain associated property. At March 31, 2016, CECONY had costs of $96 million in utility construction work in progress related to the projects. The projects are targeted to be in-service in June 2016.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
New Financial Accounting Standards	New Financial Accounting Standards In May 2014, the FASB and the International Accounting Standards Board (IASB) jointly issued a revenue recognition standard that will supersede the revenue recognition requirements within Accounting Standards Codification Topic 605, “Revenue Recognition,” and most industry-specific guidance under the Codification through Accounting Standards Update (ASU) No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” The purpose of the new guidance is to create a consistent framework for revenue recognition. The guidance clarifies how to measure and recognize revenue arising from customer contracts to depict the transfer of goods or services in an amount that reflects the consideration the entity expects to receive. Additionally, in March and April 2016, respectively, the FASB issued ASU No. 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal Versus Agent Considerations (Reporting Revenue Gross Versus Net)” to clarify how to apply the implementation guidance for principal versus agent considerations and ASU No. 2016-10, “Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing” to clarify the guidance pertaining to identifying performance obligations and licensing implementation guidance. The new standard is effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for reporting periods beginning after December 15, 2016. The Companies are in the process of evaluating the application and impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In January 2016, the FASB issued amendments on certain aspects of recognition, measurement, presentation, and disclosure of financial instruments through ASU No. 2016-01, “Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments require changes to the accounting for equity investments, the presentation and disclosure requirements for financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, clarification was provided related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. For public entities, the amendments are effective for reporting periods beginning after December 15, 2017. Early adoption is permitted for portions of the standard. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2016, the FASB issued amendments on financial reporting of leasing transactions through ASU No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model. For income statement purposes, the pattern of expense recognition will be dependent on whether transactions are designated as operating leases or finance leases. The amendments are effective for reporting periods beginning after December 15, 2018. Early adoption is permitted. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to the guidance for Derivatives and Hedging accounting through ASU 2016-05, “Derivatives and Hedging (Topic 815): Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships." The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as a hedging instrument under Topic 815 does not, in and of itself, require discontinuation of the application of hedge accounting. The amendments in this update are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to clarify the guidance for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts through ASU No. 2016-06, “Derivatives & Hedging (Topic 815): Contingent Put and Call Options in Debt Instruments.” An entity performing the assessment under the amendments is required to assess the embedded call (put) options solely in accordance with the four-step decision sequence. The amendments are effective for financial statements issued for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to eliminate the requirement to retroactively adopt the equity method of accounting when a company increases its level of ownership or degree of influence over an investment through ASU No. 2016-07, “Investments-Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting.” This amendment requires that an entity that has an available-for-sale equity security that becomes qualified for the equity method of accounting recognize through earnings the unrealized holding gain or loss in Accumulated Other Comprehensive Income at the date the investment qualifies for the equity method. The amendments in this Update are effective for reporting periods beginning after December 15, 2016. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity. In March 2016, the FASB issued amendments to simplify several aspects of the accounting for share-based payment transactions through ASU No. 2016-09, “Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” The amendments simplify areas such as income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The amendments are effective for reporting periods beginning after December 15, 2016. Early adoption is permitted. The application of this guidance is not expected to have a material impact on the Companies’ financial position, results of operations and liquidity.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Earnings Per Common Share	For the three months ended March 31, 2016 and 2015 , basic and diluted earnings per share (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) 2016 2015 Net income $310 $370 Weighted average common shares outstanding – basic 293.7 292.9 Add: Incremental shares attributable to effect of potentially dilutive securities 1.1 1.0 Adjusted weighted average common shares outstanding – diluted 294.8 293.9 Net Income per common share – basic $1.05 $1.26 Net Income per common share – diluted $1.05 $1.26
Changes in Accumulated Other Comprehensive Income/(Loss) by Component	For the three months ended March 31, 2016 and 2015 , 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) 2016 2015 2016 2015 Beginning balance, accumulated OCI, net of taxes (a) $(34) $(45) $(9) $(11) OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively (1) 3 — — Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015 (a)(b) 1 2 — — Current period OCI, net of taxes — 5 — — Ending balance, accumulated OCI, net of taxes $(34) $(40) $(9) $(11) (a) Tax reclassified from accumulated OCI is reported in the income tax expense line item of the 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, 2016
Regulated Operations [Abstract]
Regulatory Assets and Liabilities	Regulatory assets and liabilities at March 31, 2016 and December 31, 2015 were comprised of the following items: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Regulatory assets Unrecognized pension and other postretirement costs $3,663 $3,876 $3,502 $3,697 Future income tax 2,363 2,350 2,246 2,232 Environmental remediation costs 851 904 746 800 Revenue taxes 293 253 279 240 Deferred storm costs 154 185 84 110 Deferred derivative losses 106 50 97 46 Surcharge for New York State assessment 55 44 50 40 Unamortized loss on reacquired debt 48 50 46 48 O&R property tax reconciliation 44 46 — — Pension and other postretirement benefits deferrals 41 45 11 16 Net electric deferrals 39 44 39 44 Preferred stock redemption 26 26 26 26 O&R transition bond charges 19 21 — — Workers’ compensation 16 11 16 11 Recoverable energy costs — 16 — 15 Other 212 175 194 157 Regulatory assets – noncurrent 7,930 8,096 7,336 7,482 Deferred derivative losses 143 113 131 103 Recoverable energy costs 9 19 8 18 Regulatory assets – current 152 132 139 121 Total Regulatory Assets $8,082 $8,228 $7,475 $7,603 Regulatory liabilities Allowance for cost of removal less salvage $693 $676 $586 $570 Property tax reconciliation 259 303 259 303 Prudence proceeding 98 99 98 99 Unrecognized other postretirement costs 96 28 96 28 Base rate change deferrals 95 128 95 128 Pension and other postretirement benefit deferrals 89 76 59 46 New York State income tax rate change 71 75 69 72 Variable-rate tax-exempt debt – cost rate reconciliation 67 70 58 60 Carrying charges on repair allowance and bonus depreciation 51 49 49 48 Net unbilled revenue deferrals 44 109 44 109 Property tax refunds 33 44 33 44 Net utility plant reconciliations 30 32 30 31 Earnings sharing – electric and steam 27 80 27 80 World Trade Center settlement proceeds 15 21 15 21 Other 190 187 154 150 Regulatory liabilities – noncurrent 1,858 1,977 1,672 1,789 Revenue decoupling mechanism 69 45 69 45 Refundable energy costs 53 64 26 33 Deferred derivative gains 3 6 2 6 Regulatory liabilities – current 125 115 97 84 Total Regulatory Liabilities $1,983 $2,092 $1,769 $1,873

Capitalization (Tables)

Capitalization (Tables)	3 Months Ended
	Mar. 31, 2016
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, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Long-Term Debt (including current portion) Carrying Amount Fair Value Carrying Amount Fair Value Con Edison $12,961 $14,710 $12,745 $13,856 CECONY $11,438 $12,995 $11,437 $12,427

Pension Benefits (Tables)

Pension Benefits (Tables)	3 Months Ended
	Mar. 31, 2016
Pension Benefits
Total Periodic Benefit Costs	The components of the Companies’ total periodic benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost – including administrative expenses $69 $74 $65 $70 Interest cost on projected benefit obligation 149 144 140 135 Expected return on plan assets (237) (222) (225) (210) Recognition of net actuarial loss 149 194 141 183 Recognition of prior service costs 1 1 — — TOTAL PERIODIC BENEFIT COST $131 $191 $121 $178 Cost capitalized (52) (68) (49) (65) Reconciliation to rate level 12 (24) 13 (24) Cost charged to operating expenses $91 $99 $85 $89

Other Postretirement Benefits (

Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2016
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total Periodic Benefit Costs	The components of the Companies’ total periodic other postretirement benefit costs for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Service cost $4 $5 $3 $4 Interest cost on accumulated other postretirement benefit obligation 12 13 10 11 Expected return on plan assets (19) (20) (17) (17) Recognition of net actuarial loss 1 8 1 7 Recognition of prior service cost (5) (5) (4) (4) TOTAL PERIODIC OTHER POSTRETIREMENT BENEFIT COST $(7) $1 $(7) $1 Cost capitalized 2 (1) 2 (1) Reconciliation to rate level 7 4 7 2 Cost charged to operating expenses $2 $4 $2 $2

Environmental Matters (Tables)

Environmental Matters (Tables)	3 Months Ended
	Mar. 31, 2016
Environmental Remediation Obligations [Abstract]
Accrued Liabilities and Regulatory Assets	The accrued liabilities and regulatory assets related to Superfund Sites at March 31, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued Liabilities: Manufactured gas plant sites $678 $679 $578 $579 Other Superfund Sites 89 86 89 86 Total $767 $765 $667 $665 Regulatory assets $851 $904 $746 $800
Environmental Remediation Costs	Environmental remediation costs incurred related to Superfund Sites for the three months ended March 31, 2016 and 2015 were as follows: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Remediation costs incurred $3 $7 $3 $6
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, 2016 and December 31, 2015 were as follows: Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Accrued liability – asbestos suits $8 $8 $7 $7 Regulatory assets – asbestos suits $8 $8 $7 $7 Accrued liability – workers’ compensation $91 $86 $86 $81 Regulatory assets – workers’ compensation $16 $11 $16 $11

Other Material Contingencies (T

Other Material Contingencies (Tables)	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Total Guarantees	A summary, by type and term, of Con Edison’s total guarantees at March 31, 2016 is as follows: Guarantee Type 0 – 3 years 4 – 10 years > 10 years Total (Millions of Dollars) Con Edison Transmission $791 $592 $— $1,383 Energy transactions 707 41 90 838 Renewable electric production projects 388 — 21 409 Other 75 — — 75 Total $1,961 $633 $111 $2,705

Financial Information by Busi33

Financial Information by Business Segment (Tables)	3 Months Ended
	Mar. 31, 2016
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 (Millions of Dollars) 2016 2015 2016 2015 2016 2015 2016 2015 CECONY Electric $1,773 $1,980 $4 $4 $213 $202 $273 $279 Gas 601 655 1 1 38 35 253 241 Steam 258 375 22 22 21 20 114 164 Consolidation adjustments — — (27) (27) — — — — Total CECONY $2,632 $3,010 $— $— $272 $257 $640 $684 O&R Electric $140 $156 $— $— $12 $12 $18 $18 Gas 75 77 — — 5 5 35 27 Total O&R $215 $233 $— $— $17 $17 $53 $45 Competitive energy businesses $310 $374 $6 $(3) $9 $5 $(51) $(3) Other (a) (1) (1) (6) 3 (1) — — — Total Con Edison $3,156 $3,616 $— $— $297 $279 $642 $726 (a) Parent company, consolidation adjustments and Con Edison Transmission. Other does not represent a business segment.

Derivative Instruments and He34

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values of Commodity Derivatives Including Offsetting Assets	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Balance Sheet Location Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Con Edison Fair value of derivative assets Current $42 $(34) $8 (b) $59 $(41) $18 (b) Current - assets held for sale (c) 55 (54) 1 51 (50) 1 Noncurrent 25 (24) 1 57 (54) 3 Noncurrent - assets held for sale (c) 13 (13) — 15 (15) — Total fair value of derivative assets $135 $(125) $10 $182 $(160) $22 Fair value of derivative liabilities Current $(169) $79 $(90) $(144) $78 $(66) Current - liabilities held for sale (c) (152) 54 (98) (115) 50 (65) Noncurrent (128) 36 (92) (102) 63 (39) Noncurrent - liabilities held for sale (c) (54) 13 (41) (28) 15 (13) Total fair value of derivative liabilities $(503) $182 $(321) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(368) $57 $(311) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $25 $(23) $2 (b) $40 $(32) $8 (b) Noncurrent 15 (15) — 48 (47) 1 Total fair value of derivative assets $40 $(38) $2 $88 $(79) $9 Fair value of derivative liabilities Current $(145) $69 $(76) $(121) $71 $(50) Noncurrent (112) 28 (84) (92) 56 (36) Total fair value of derivative liabilities $(257) $97 $(160) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(217) $59 $(158) (b) $(125) $48 $(77) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At March 31, 2016 and December 31, 2015 , margin deposits for Con Edison ( $18 million and $26 million , respectively) and CECONY ( $18 million and $26 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet (see Note O).
Fair Values of Commodity Derivatives Including Offsetting Liabilities	The fair values of the Companies’ commodity derivatives including the offsetting of assets and liabilities on the consolidated balance sheet at March 31, 2016 and December 31, 2015 were: (Millions of Dollars) 2016 2015 Balance Sheet Location Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Gross Amounts of Recognized Assets/(Liabilities) Gross Amounts Offset Net Amounts of Assets/ (Liabilities) (a) Con Edison Fair value of derivative assets Current $42 $(34) $8 (b) $59 $(41) $18 (b) Current - assets held for sale (c) 55 (54) 1 51 (50) 1 Noncurrent 25 (24) 1 57 (54) 3 Noncurrent - assets held for sale (c) 13 (13) — 15 (15) — Total fair value of derivative assets $135 $(125) $10 $182 $(160) $22 Fair value of derivative liabilities Current $(169) $79 $(90) $(144) $78 $(66) Current - liabilities held for sale (c) (152) 54 (98) (115) 50 (65) Noncurrent (128) 36 (92) (102) 63 (39) Noncurrent - liabilities held for sale (c) (54) 13 (41) (28) 15 (13) Total fair value of derivative liabilities $(503) $182 $(321) $(389) $206 $(183) Net fair value derivative assets/(liabilities) $(368) $57 $(311) (b) $(207) $46 $(161) (b) CECONY Fair value of derivative assets Current $25 $(23) $2 (b) $40 $(32) $8 (b) Noncurrent 15 (15) — 48 (47) 1 Total fair value of derivative assets $40 $(38) $2 $88 $(79) $9 Fair value of derivative liabilities Current $(145) $69 $(76) $(121) $71 $(50) Noncurrent (112) 28 (84) (92) 56 (36) Total fair value of derivative liabilities $(257) $97 $(160) $(213) $127 $(86) Net fair value derivative assets/(liabilities) $(217) $59 $(158) (b) $(125) $48 $(77) (b) (a) Derivative instruments and collateral were offset on the consolidated balance sheet as applicable under the accounting rules. The Companies enter into master agreements for their commodity derivatives. These agreements typically provide offset in the event of contract termination. In such case, generally the non-defaulting party’s payable will be offset by the defaulting party’s payable. The non-defaulting party will customarily notify the defaulting party within a specific time period and come to an agreement on the early termination amount. (b) At March 31, 2016 and December 31, 2015 , margin deposits for Con Edison ( $18 million and $26 million , respectively) and CECONY ( $18 million and $26 million , respectively) were classified as derivative assets on the consolidated balance sheet, but not included in the table. Margin is collateral, typically cash, that the holder of a derivative instrument is required to deposit in order to transact on an exchange and to cover its potential losses with its broker or the exchange. (c) Amounts represent derivative assets and liabilities included in assets and liabilities held for sale on the consolidated balance sheet (see Note O).
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, 2016 and 2015 : For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) Balance Sheet Location 2016 2015 2016 2015 Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations: Current Deferred derivative gains $(4) $3 $(4) $3 Noncurrent Deferred derivative gains — — (1) — Total deferred gains/(losses) $(4) $3 $(5) $3 Current Deferred derivative losses $(30) $43 $(28) $41 Current Recoverable energy costs (73) — (66) (2) Noncurrent Deferred derivative losses (56) (19) (51) (16) Total deferred gains/(losses) $(159) $24 $(145) $23 Net deferred gains/(losses) $(163) $27 $(150) $26 Income Statement Location Pre-tax gain/(loss) recognized in income Purchased power expense $(114) (a) $21 (b) $— $— Gas purchased for resale (10) (42) — — Non-utility revenue 11 (a) 42 (b) — — Total pre-tax gain/(loss) recognized in income $(113) $21 $— $— (a) 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). (b) For the three months ended March 31, 2015 , Con Edison recorded unrealized pre-tax gains and losses in non-utility operating revenue ( $4 million loss) and purchased power expense ( $12 million gain).
Hedged Volume of Derivative Transactions	The following table presents the hedged volume of Con Edison’s and CECONY’s derivative transactions at March 31, 2016 : Electric Energy (MWh) (a)(b) Capacity (MW) (a) Natural Gas (Dt) (a)(b) Refined Fuels (gallons) Con Edison (c) 34,331,960 26,658 43,472,324 5,376,000 CECONY 17,173,925 12,000 40,280,000 5,376,000 (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. (c) Includes 15,495,945 MWh for electric energy, 11,817 MW for capacity and 552,073 Dt for natural gas derivative transactions that are held for sale.
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, 2016 : (Millions of Dollars) Con Edison (a) CECONY (a) Aggregate fair value – net liabilities $187 $152 Collateral posted 45 44 Additional collateral (b) (downgrade one level from current ratings) 30 20 Additional collateral (b) (downgrade to below investment grade from current ratings) 192 (c) 148 (c) (a) Non-derivative transactions for the purchase and sale of electricity and gas and qualifying derivative instruments, which have been designated as normal purchases or normal sales, are excluded from the table. These transactions primarily include purchases of electricity from independent system operators. In the event the Utilities and the competitive energy businesses were no longer extended unsecured credit for such purchases, the Companies would be required to post additional collateral of $7 million at March 31, 2016 . For certain other such non-derivative transactions, the Companies could be required to post collateral under certain circumstances, including in the event counterparties had reasonable grounds for insecurity. (b) The Companies measure the collateral requirements by taking into consideration the fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liabilities position plus amounts owed to counterparties for settled transactions and amounts required by counterparties for minimum financial security. The fair value amounts represent unrealized losses, net of any unrealized gains where the Companies have a legally enforceable right to offset. (c) Derivative instruments that are net assets have been excluded from the table. At March 31, 2016 , if Con Edison had been downgraded to below investment grade, it would have been required to post additional collateral for such derivative instruments of $16 million .

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 are summarized below. 2016 2015 (Millions of Dollars) Level 1 Level 2 Level 3 Netting Adjustment (e) Total Level 1 Level 2 Level 3 Netting Adjustment (e) Total Con Edison Derivative assets: Commodity (a)(b)(c) $— $19 $6 $2 $27 $2 $25 $13 $7 $47 Commodity held for sale (f) — 51 2 (52) 1 — 63 1 (63) 1 Other (a)(b)(d) 174 113 — — 287 185 112 — — 297 Total assets $174 $183 $8 $(50) $315 $187 $200 $14 $(56) $345 Derivative liabilities: Commodity (a)(b)(c) $12 $241 $2 $(73) $182 $16 $153 $1 $(65) $105 Commodity held for sale (f) 1 180 10 (52) 139 1 133 7 (63) 78 Total liabilities $13 $421 $12 $(125) $321 $17 $286 $8 $(128) $183 CECONY Derivative assets: Commodity (a)(b)(c) $— $2 $2 $16 $20 $1 $9 $8 $17 $35 Other (a)(b)(d) 160 106 — — 266 171 105 — — 276 Total assets $160 $108 $2 $16 $286 $172 $114 $8 $17 $311 Derivative liabilities: Commodity (a)(b)(c) $12 $209 $— $(61) $160 $14 $129 $— $(57) $86 (a) The Companies’ policy is to review the fair value hierarchy and recognize transfers into and transfers out of the levels at the end of each reporting period. There were no transfers between levels 1, 2 and 3 for the three months ended March 31, 2016 and for the year ended December 31, 2015 . (b) Level 2 assets and liabilities include investments held in the deferred compensation plan and/or non-qualified retirement plans, exchange-traded contracts where there is insufficient market liquidity to warrant inclusion in Level 1, certain over-the-counter derivative instruments for electricity, refined products and natural gas. Derivative instruments classified as Level 2 are valued using industry standard models that incorporate corroborated observable inputs; such as pricing services or prices from similar instruments that trade in liquid markets, time value and volatility factors. (c) The accounting rules for fair value measurements and disclosures require consideration of the impact of nonperformance risk (including credit risk) from a market participant perspective in the measurement of the fair value of assets and liabilities. At March 31, 2016 and December 31, 2015 , the Companies determined that nonperformance risk would have no material impact on their financial position or results of operations. (d) Other assets are comprised of assets such as life insurance contracts within the deferred compensation plan and non-qualified retirement plans. (e) Amounts represent the impact of legally-enforceable master netting agreements that allow the Companies to net gain and loss positions and cash collateral held or placed with the same counterparties. (f) Amounts represent derivative assets and liabilities included in Assets and Liabilities held for sale on the consolidated balance sheet (see Note O).
Schedule of Commodity Derivatives	The risk management group reports to the Companies’ Vice President and Treasurer. Fair Value of Level 3 at March 31, 2016 Valuation Techniques Unobservable Inputs Range (Millions of Dollars) Con Edison – Commodity Electricity $(7) Discounted Cash Flow Forward energy prices (a) $15.32-$74.99 per MWh Discounted Cash Flow Forward capacity prices (a) $0.58-$8.10 per kW-month Transmission Congestion Contracts/Financial Transmission Rights 3 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% Inter-zonal forward price curves adjusted for historical zonal losses (b) $(5.10)-$2.25 per MWh Total Con Edison—Commodity $(4) CECONY—Commodity Transmission Congestion Contracts $2 Discounted Cash Flow Discount to adjust auction prices for inter-zonal forward price curves (b) 40.8%-62.1% Discount to adjust auction prices for historical monthly realized settlements (b) 1.6%-82.2% (a) Generally, increases/(decreases) in this input in isolation would result in a higher/(lower) fair value measurement. (b) Generally, increases/(decreases) in this input in isolation would result in a lower/(higher) fair value measurement.
Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value	The table listed below provides a reconciliation of the beginning and ending net balances for assets and liabilities measured at fair value as of March 31, 2016 and 2015 and classified as Level 3 in the fair value hierarchy: For the Three Months Ended March 31, Con Edison CECONY (Millions of Dollars) 2016 2015 2016 2015 Beginning balance as of January 1, $6 $20 $8 $13 Included in earnings (7) (10) (1) (2) Included in regulatory assets and liabilities (3) — (4) — Purchases — 3 — 2 Settlements — (2) (1) (1) Ending balance as of March 31, $(4) $11 $2 $12

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Summary of VIEs	The following table summarizes the VIEs in which Con Edison Development has entered into as of March 31, 2016 : Project Name (a) Generating Capacity (b) (MW AC) Power Purchase Agreement Term (in Years) Year of Initial Investment Location Maximum Exposure to Loss ( Millions of Dollars ) (c) Copper Mountain Solar 3 128 20 2014 Nevada $183 Panoche Valley 124 20 2015 California 133 Mesquite Solar 1 83 20 2013 Arizona 99 Copper Mountain Solar 2 75 25 2013 Nevada 82 California Solar 55 25 2012 California 65 Broken Bow II 38 25 2014 Nebraska 54 Texas Solar 4 32 25 2014 Texas 15 Pilesgrove 9 n/a (d) 2010 New Jersey 26 (a) With the exception of Texas Solar 4, Con Edison’s ownership interest is 50 percent and these projects are accounted for using the equity method of accounting. Con Edison is not the primary beneficiary since the power to direct the activities that most significantly impact the economics of the entities are shared equally between Con Edison Development and third parties. Con Edison’s ownership interest in Texas Solar 4 is 80 percent and is consolidated in the financial statements. Con Edison is the primary beneficiary since the power to direct the activities that most significantly impact the economics of Texas Solar 4 is held by Con Edison Development. The maximum exposure for Texas Solar 4 is the net assets of the investment offset by an $8 million noncontrolling interest. (b) Represents Con Edison Development’s ownership interest in the project. (c) For investments accounted for under the equity method, maximum exposure is equal to the carrying value of the investment on the consolidated balance sheet and any related receivables due from the project. For consolidated investments, maximum exposure is equal to the net assets of the investment on the consolidated balance sheet less any applicable noncontrolling interest. Con Edison did not provide any financial or other support during the year that was not previously contractually required. (d) Pilesgrove has 3 - 4 year Solar Renewable Energy Credit hedges in place.

Assets Held For Sale (Tables)

Assets Held For Sale (Tables)	3 Months Ended
	Mar. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	At March 31, 2016 , the carrying amounts of the assets and liabilities designated as held for sale were as follows: (Millions of Dollars) Retail Electric Supply Business Pike Total Cash and temporary cash investments $— $7 $7 Accounts receivable less allowance for uncollectible accounts of $2 67 — 67 Accrued unbilled revenue 67 1 68 Other assets 2 1 3 Total current assets 136 9 145 Utility plant, less accumulated depreciation of $6 — 14 14 Non-utility property, less accumulated depreciation of $13 3 — 3 Non-utility property construction work in progress 1 — 1 Regulatory assets — 3 3 Total assets held for sale $140 $26 $166 Fair value of derivative liabilities $98 $— $98 Accounts payable 3 — 3 Other 3 2 5 Total current liabilities 104 2 106 Fair value of derivative liabilities 41 — 41 Long-term debt — 3 3 Total liabilities held for sale $145 $5 $150

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accounting Policies [Abstract]
Net income	$ 310	$ 370
Weighted average common shares outstanding – basic	293.7	292.9
Add: Incremental shares attributable to effect of potentially dilutive securities	1.1	1
Adjusted weighted average common shares outstanding – diluted	294.8	293.9
Net income per common share-basic (dollars per share)	$ 1.05	$ 1.26
Net income per common share-diluted (dollars per share)	$ 1.05	$ 1.26

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Income/(Loss) by Component (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 13,061	$ 12,585
Current period OCI, net of taxes	0	5
Ending Balance	13,201	12,770
OCI before reclassifications, tax	1	(2)
Amounts reclassified from accumulated OCI related to pension plan liabilities, tax	(1)	(1)
CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Current period OCI, net of taxes	0	0
Accumulated Other Comprehensive Income/(Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(34)	(45)
OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively	(1)	3
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015	1	2
Current period OCI, net of taxes	0	5
Ending Balance	(34)	(40)
Accumulated Other Comprehensive Income/(Loss) | CECONY
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(9)	(11)
OCI before reclassifications, net of tax of $1 and $(2) for Con Edison in 2016 and 2015, respectively	0	0
Amounts reclassified from accumulated OCI related to pension plan liabilities, net of tax of $(1) for Con Edison in 2016 and 2015	0	0
Current period OCI, net of taxes	0	0
Ending Balance	$ (9)	$ (11)

Regulatory Matters - Summary of

Regulatory Matters - Summary of Rate Plan (Detail) - CECONY $ in Millions	1 Months Ended
	Mar. 31, 2016USD ($)
Year 1 | Electric
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	$ 2
Public utilities, requested rate increase (decrease), amount	480
Year 1 | Gas
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	5
Public utilities, requested rate increase (decrease), amount	159
Year 2 | Electric
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	3
Public utilities, requested rate increase (decrease), amount	177
Year 2 | Gas
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	(4)
Public utilities, requested rate increase (decrease), amount	93
Year 3 | Electric
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amount	141
Year 3 | Gas
Public Utilities, General Disclosures [Line Items]
Increase (decrease) in requested rate amount	(5)
Public utilities, requested rate increase (decrease), amount	$ 104

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Public Utilities, General Disclosures [Line Items]
Expected credit to customers	$ 116,000,000
Return on capital expenditures, not recoverable (up to)	55,000,000
Regulatory liabilities	1,858,000,000	$ 1,977,000,000
Prudence proceeding
Public Utilities, General Disclosures [Line Items]
Regulatory liabilities	$ 98,000,000	$ 99,000,000

Regulatory Matters - Regulatory

Regulatory Matters - Regulatory Assets and Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Regulatory assets
Regulatory assets – noncurrent	$ 7,930	$ 8,096
Regulatory assets – current	152	132
Total Regulatory Assets	8,082	8,228
Regulatory liabilities
Regulatory liabilities – noncurrent	1,858	1,977
Regulatory liabilities – current	125	115
Total Regulatory Liabilities	1,983	2,092
Allowance for cost of removal less salvage
Regulatory liabilities
Regulatory liabilities – noncurrent	693	676
Property tax reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	259	303
Prudence proceeding
Regulatory liabilities
Regulatory liabilities – noncurrent	98	99
Unrecognized other postretirement costs
Regulatory liabilities
Regulatory liabilities – noncurrent	96	28
Base rate change deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	95	128
Pension and other postretirement benefit deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	89	76
New York State income tax rate change
Regulatory liabilities
Regulatory liabilities – noncurrent	71	75
Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	67	70
Carrying charges on repair allowance and bonus depreciation
Regulatory liabilities
Regulatory liabilities – noncurrent	51	49
Net unbilled revenue deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	44	109
Property tax refunds
Regulatory liabilities
Regulatory liabilities – noncurrent	33	44
Net utility plant reconciliations
Regulatory liabilities
Regulatory liabilities – noncurrent	30	32
Earnings sharing – electric and steam
Regulatory liabilities
Regulatory liabilities – noncurrent	27	80
World Trade Center settlement proceeds
Regulatory liabilities
Regulatory liabilities – noncurrent	15	21
Other
Regulatory liabilities
Regulatory liabilities – noncurrent	190	187
Revenue decoupling mechanism
Regulatory liabilities
Regulatory liabilities – current	69	45
Refundable energy costs
Regulatory liabilities
Regulatory liabilities – current	53	64
Deferred derivative gains
Regulatory liabilities
Regulatory liabilities – current	3	6
Unrecognized pension and other postretirement costs
Regulatory assets
Regulatory assets – noncurrent	3,663	3,876
Future income tax
Regulatory assets
Regulatory assets – noncurrent	2,363	2,350
Revenue taxes
Regulatory assets
Regulatory assets – noncurrent	293	253
Deferred storm costs
Regulatory assets
Regulatory assets – noncurrent	154	185
Deferred derivative losses
Regulatory assets
Regulatory assets – noncurrent	106	50
Surcharge for New York State assessment
Regulatory assets
Regulatory assets – noncurrent	55	44
Unamortized loss on reacquired debt
Regulatory assets
Regulatory assets – noncurrent	48	50
O&R property tax reconciliation
Regulatory assets
Regulatory assets – noncurrent	44	46
Pension and other postretirement benefits deferrals
Regulatory assets
Regulatory assets – noncurrent	41	45
Net electric deferrals
Regulatory assets
Regulatory assets – noncurrent	39	44
Preferred stock redemption
Regulatory assets
Regulatory assets – noncurrent	26	26
O&R transition bond charges
Regulatory assets
Regulatory assets – noncurrent	19	21
Recoverable energy costs
Regulatory assets
Regulatory assets – noncurrent	0	16
Regulatory assets – current	9	19
Other
Regulatory assets
Regulatory assets – noncurrent	212	175
Deferred derivative losses
Regulatory assets
Regulatory assets – current	143	113
CECONY
Regulatory assets
Regulatory assets – noncurrent	7,336	7,482
Regulatory assets – current	139	121
Total Regulatory Assets	7,475	7,603
Regulatory liabilities
Regulatory liabilities – noncurrent	1,672	1,789
Regulatory liabilities – current	97	84
Total Regulatory Liabilities	1,769	1,873
CECONY | Allowance for cost of removal less salvage
Regulatory liabilities
Regulatory liabilities – noncurrent	586	570
CECONY | Property tax reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	259	303
CECONY | Prudence proceeding
Regulatory liabilities
Regulatory liabilities – noncurrent	98	99
CECONY | Unrecognized other postretirement costs
Regulatory liabilities
Regulatory liabilities – noncurrent	96	28
CECONY | Base rate change deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	95	128
CECONY | Pension and other postretirement benefit deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	59	46
CECONY | New York State income tax rate change
Regulatory liabilities
Regulatory liabilities – noncurrent	69	72
CECONY | Variable-rate tax-exempt debt – cost rate reconciliation
Regulatory liabilities
Regulatory liabilities – noncurrent	58	60
CECONY | Carrying charges on repair allowance and bonus depreciation
Regulatory liabilities
Regulatory liabilities – noncurrent	49	48
CECONY | Net unbilled revenue deferrals
Regulatory liabilities
Regulatory liabilities – noncurrent	44	109
CECONY | Property tax refunds
Regulatory liabilities
Regulatory liabilities – noncurrent	33	44
CECONY | Net utility plant reconciliations
Regulatory liabilities
Regulatory liabilities – noncurrent	30	31
CECONY | Earnings sharing – electric and steam
Regulatory liabilities
Regulatory liabilities – noncurrent	27	80
CECONY | World Trade Center settlement proceeds
Regulatory liabilities
Regulatory liabilities – noncurrent	15	21
CECONY | Other
Regulatory liabilities
Regulatory liabilities – noncurrent	154	150
CECONY | Revenue decoupling mechanism
Regulatory liabilities
Regulatory liabilities – current	69	45
CECONY | Refundable energy costs
Regulatory liabilities
Regulatory liabilities – current	26	33
CECONY | Deferred derivative gains
Regulatory liabilities
Regulatory liabilities – current	2	6
CECONY | Unrecognized pension and other postretirement costs
Regulatory assets
Regulatory assets – noncurrent	3,502	3,697
CECONY | Future income tax
Regulatory assets
Regulatory assets – noncurrent	2,246	2,232
CECONY | Revenue taxes
Regulatory assets
Regulatory assets – noncurrent	279	240
CECONY | Deferred storm costs
Regulatory assets
Regulatory assets – noncurrent	84	110
CECONY | Deferred derivative losses
Regulatory assets
Regulatory assets – noncurrent	97	46
CECONY | Surcharge for New York State assessment
Regulatory assets
Regulatory assets – noncurrent	50	40
CECONY | Unamortized loss on reacquired debt
Regulatory assets
Regulatory assets – noncurrent	46	48
CECONY | O&R property tax reconciliation
Regulatory assets
Regulatory assets – noncurrent	0	0
CECONY | Pension and other postretirement benefits deferrals
Regulatory assets
Regulatory assets – noncurrent	11	16
CECONY | Net electric deferrals
Regulatory assets
Regulatory assets – noncurrent	39	44
CECONY | Preferred stock redemption
Regulatory assets
Regulatory assets – noncurrent	26	26
CECONY | O&R transition bond charges
Regulatory assets
Regulatory assets – noncurrent	0	0
CECONY | Recoverable energy costs
Regulatory assets
Regulatory assets – noncurrent	0	15
Regulatory assets – current	8	18
CECONY | Other
Regulatory assets
Regulatory assets – noncurrent	194	157
CECONY | Deferred derivative losses
Regulatory assets
Regulatory assets – current	131	103
Superfund Sites
Regulatory assets
Total Regulatory Assets	851	904
Superfund Sites | Environmental remediation costs
Regulatory assets
Regulatory assets – noncurrent	851	904
Superfund Sites | CECONY
Regulatory assets
Total Regulatory Assets	746	800
Superfund Sites | CECONY | Environmental remediation costs
Regulatory assets
Regulatory assets – noncurrent	746	800
Workers’ compensation
Regulatory assets
Total Regulatory Assets	16	11
Workers’ compensation | Workers’ compensation
Regulatory assets
Regulatory assets – noncurrent	16	11
Workers’ compensation | CECONY
Regulatory assets
Total Regulatory Assets	16	11
Workers’ compensation | CECONY | Workers’ compensation
Regulatory assets
Regulatory assets – noncurrent	$ 16	$ 11

Capitalization - Carrying Amoun

Capitalization - Carrying Amounts and Fair Values of Long-Term Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Carrying Amount	$ 12,961	$ 12,745
Fair Value	14,710	13,856
CECONY
Debt Instrument [Line Items]
Carrying Amount	11,438	11,437
Fair Value	$ 12,995	$ 12,427

Capitalization - Additional Inf

Capitalization - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Feb. 29, 2016	Dec. 31, 2015
Schedule of Capitalization [Line Items]
Long-term debt, fair value	$ 14,710,000,000		$ 13,856,000,000
Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value	14,074,000,000
Level 3
Schedule of Capitalization [Line Items]
Long-term debt, fair value	636,000,000
CECONY
Schedule of Capitalization [Line Items]
Long-term debt, fair value	12,995,000,000		$ 12,427,000,000
CECONY | Level 2
Schedule of Capitalization [Line Items]
Long-term debt, fair value	12,359,000,000
CECONY | Level 3
Schedule of Capitalization [Line Items]
Long-term debt, fair value	636,000,000
Tax-exempt debt	$ 636,000,000
Senior Notes | 4.21% Senior Notes due 2041 | Con Edison Development
Schedule of Capitalization [Line Items]
Debt Instrument, face amount		$ 218,000,000
Debt instrument, interest rate (percent)		4.21%

Short-Term Borrowing - Addition

Short-Term Borrowing - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Commercial paper, outstanding	$ 1,199,000,000	$ 1,529,000,000
Weighted average interest rate (percent)	0.70%	0.70%
Loans outstanding under credit agreement	$ 0	$ 0
Letters of credit outstanding under the Credit Agreement	2,000,000	15,000,000
CECONY
Short-term Debt [Line Items]
Commercial paper, outstanding	520,000,000	$ 1,033,000,000
Weighted average interest rate (percent)		0.70%
Letters of credit outstanding under the Credit Agreement	$ 2,000,000

Pension Benefits - Total Period

Pension Benefits - Total Periodic Benefit Costs (Detail) - Pension Benefits - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	$ 69	$ 74
Interest cost on projected benefit obligation	149	144
Expected return on plan assets	(237)	(222)
Recognition of net actuarial loss	149	194
Recognition of prior service costs	1	1
TOTAL PERIODIC BENEFIT COST	131	191
Cost capitalized	(52)	(68)
Reconciliation to rate level	12	(24)
Cost charged to operating expenses	91	99
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost – including administrative expenses	65	70
Interest cost on projected benefit obligation	140	135
Expected return on plan assets	(225)	(210)
Recognition of net actuarial loss	141	183
Recognition of prior service costs	0	0
TOTAL PERIODIC BENEFIT COST	121	178
Cost capitalized	(49)	(65)
Reconciliation to rate level	13	(24)
Cost charged to operating expenses	$ 85	$ 89

Pension Benefits - Additional I

Pension Benefits - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 507
Contributions	153
CECONY | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	469
CECONY | Non-qualified Supplemental Plan
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 17

Other Postretirement Benefits -

Other Postretirement Benefits - Total Periodic Postretirement Benefit Costs (Detail) - Other Postretirement Benefits - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5
Interest cost on accumulated other postretirement benefit obligation	12	13
Expected return on plan assets	(19)	(20)
Recognition of net actuarial loss	1	8
Recognition of prior service cost	(5)	(5)
NET PERIODIC BENEFIT COST	(7)	1
Cost capitalized	2	(1)
Reconciliation to rate level	7	4
Cost charged to operating expenses	2	4
CECONY
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	4
Interest cost on accumulated other postretirement benefit obligation	10	11
Expected return on plan assets	(17)	(17)
Recognition of net actuarial loss	1	7
Recognition of prior service cost	(4)	(4)
NET PERIODIC BENEFIT COST	(7)	1
Cost capitalized	2	(1)
Reconciliation to rate level	7	2
Cost charged to operating expenses	$ 2	$ 2

Other Postretirement Benefits49

Other Postretirement Benefits - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	$ 6

Environmental Matters - Accrued

Environmental Matters - Accrued Liabilities and Regulatory Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Accrued Liabilities:
Accrued Liabilities	$ 767	$ 765
Regulatory assets	8,082	8,228
Manufactured gas plant sites
Accrued Liabilities:
Accrued Liabilities	678	679
Other Superfund Sites
Accrued Liabilities:
Accrued Liabilities	89	86
Superfund Sites
Accrued Liabilities:
Accrued Liabilities	767	765
Regulatory assets	851	904
CECONY
Accrued Liabilities:
Accrued Liabilities	667	665
Regulatory assets	7,475	7,603
CECONY | Manufactured gas plant sites
Accrued Liabilities:
Accrued Liabilities	578	579
CECONY | Other Superfund Sites
Accrued Liabilities:
Accrued Liabilities	89	86
CECONY | Superfund Sites
Accrued Liabilities:
Accrued Liabilities	667	665
Regulatory assets	$ 746	$ 800

Environmental Matters - Environ

Environmental Matters - Environmental Remediation Costs (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 3	$ 7
CECONY
Environmental Exit Cost [Line Items]
Remediation costs incurred	$ 3	$ 6

Environmental Matters - Additio

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

Environmental Matters - Accru53

Environmental Matters - Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Site Contingency [Line Items]
Regulatory assets	$ 8,082	$ 8,228
Asbestos Suits
Site Contingency [Line Items]
Accrued liability	8	8
Regulatory assets	8	8
Workers’ compensation
Site Contingency [Line Items]
Accrued liability	91	86
Regulatory assets	16	11
CECONY
Site Contingency [Line Items]
Regulatory assets	7,475	7,603
CECONY | Asbestos Suits
Site Contingency [Line Items]
Accrued liability	7	7
Regulatory assets	7	7
CECONY | Workers’ compensation
Site Contingency [Line Items]
Accrued liability	86	81
Regulatory assets	$ 16	$ 11

Other Material Contingencies -

Other Material Contingencies - Additional Information (Detail)	Mar. 12, 2014buildingPersonlawsuit	Jul. 31, 2007Person	Mar. 31, 2016USD ($)lawsuit	Apr. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014
Guarantor Obligations [Line Items]
Number of person died in steam ruptured | Person		1
Number of suits pending against the company | lawsuit			80
Estimated accrued liability for suits			$ 50,000,000
Number of buildings destroyed by fire | building	2
Number of people died in explosion and fire incident | Person	8
Number of people injured in explosion and fire incident | Person	50
Guarantee obligations maximum exposure			$ 2,705,000,000		$ 2,856,000,000
Ownership interest, percentage						45.70%
Estimated project cost percentage			175.00%
Manhattan Explosion and Fire
Guarantor Obligations [Line Items]
Number of suits pending against the company | lawsuit	70
Financial And Performance Guarantee For CET Gas
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			$ 25,000,000
Financial and Performance Guarantee, Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure			75,000,000
Indemnity agreements amount			70,000,000
Electric provider obligation to Public Utility Commission of Texas			$ 5,000,000
Subsequent Event | Financial and Performance Guarantee, Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure				$ 946,000,000
Stagecoach Gas Services LLC | Subsequent Event
Guarantor Obligations [Line Items]
Equity method ownership (percent)				50.00%

Other Material Contingencies 55

Other Material Contingencies - Total Guarantees (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 2,705	$ 2,856
Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	1,383
Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	838
Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	409
Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	75
0-3 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	1,961
0-3 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	791
0-3 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	707
0-3 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	388
0-3 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	75
4-10 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	633
4-10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	592
4-10 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	41
4-10 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	0
Greater than 10 years
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	111
Greater than 10 years | Con Edison Transmission
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	0
Greater than 10 years | Energy transactions
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	90
Greater than 10 years | Renewable electric production projects
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	21
Greater than 10 years | Other
Guarantor Obligations [Line Items]
Guarantee obligations maximum exposure	$ 0

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Taxes Disclosure [Line Items]
Income tax expense	$ 164	$ 199
Effective tax rate	35.00%	35.00%
Income taxes refund	$ 10
Estimated liability for uncertain tax positions	36
Uncertain tax positions, reasonably possible to resolve within twelve months	27
Uncertain tax positions, reasonably possible to resolve within twelve months, net of federal taxes	18
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate	36
Total amount of unrecognized tax benefits, if recognized, that would reduce effective tax rate, net of federal taxes	24
CECONY
Income Taxes Disclosure [Line Items]
Income tax expense	$ 180	$ 192
Effective tax rate	37.00%	36.00%
Estimated liability for uncertain tax positions	$ 4
Uncertain tax positions, reasonably possible to resolve within twelve months	4
Uncertain tax positions, reasonably possible to resolve within twelve months, net of federal taxes	$ 3

Financial Information by Busi57

Financial Information by Business Segment - Financial Data for Business Segments (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Operating revenues	$ 3,156	$ 3,616
Depreciation and amortization	297	279
Operating income	642	726
CECONY
Segment Reporting Information [Line Items]
Operating revenues	2,632	3,010
Depreciation and amortization	272	257
Operating income	640	684
CECONY | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	213	202
Operating income	273	279
CECONY | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	38	35
Operating income	253	241
CECONY | Steam
Segment Reporting Information [Line Items]
Depreciation and amortization	21	20
Operating income	114	164
O&R
Segment Reporting Information [Line Items]
Depreciation and amortization	17	17
Operating income	53	45
O&R | Electric
Segment Reporting Information [Line Items]
Depreciation and amortization	12	12
Operating income	18	18
O&R | Gas
Segment Reporting Information [Line Items]
Depreciation and amortization	5	5
Operating income	35	27
Competitive energy businesses
Segment Reporting Information [Line Items]
Depreciation and amortization	9	5
Operating income	(51)	(3)
Other
Segment Reporting Information [Line Items]
Depreciation and amortization	(1)	0
Operating income	0	0
Operating revenues
Segment Reporting Information [Line Items]
Operating revenues	3,156	3,616
Operating revenues | CECONY
Segment Reporting Information [Line Items]
Operating revenues	2,632	3,010
Operating revenues | CECONY | Electric
Segment Reporting Information [Line Items]
Operating revenues	1,773	1,980
Operating revenues | CECONY | Gas
Segment Reporting Information [Line Items]
Operating revenues	601	655
Operating revenues | CECONY | Steam
Segment Reporting Information [Line Items]
Operating revenues	258	375
Operating revenues | O&R
Segment Reporting Information [Line Items]
Operating revenues	215	233
Operating revenues | O&R | Electric
Segment Reporting Information [Line Items]
Operating revenues	140	156
Operating revenues | O&R | Gas
Segment Reporting Information [Line Items]
Operating revenues	75	77
Operating revenues | Competitive energy businesses
Segment Reporting Information [Line Items]
Operating revenues	310	374
Operating revenues | Other
Segment Reporting Information [Line Items]
Operating revenues	(1)	(1)
Inter-segment revenues | CECONY
Segment Reporting Information [Line Items]
Operating revenues	(27)	(27)
Inter-segment revenues | CECONY | Electric
Segment Reporting Information [Line Items]
Operating revenues	4	4
Inter-segment revenues | CECONY | Gas
Segment Reporting Information [Line Items]
Operating revenues	1	1
Inter-segment revenues | CECONY | Steam
Segment Reporting Information [Line Items]
Operating revenues	22	22
Inter-segment revenues | Competitive energy businesses
Segment Reporting Information [Line Items]
Operating revenues	6	(3)
Inter-segment revenues | Other
Segment Reporting Information [Line Items]
Operating revenues	$ (6)	$ 3

Derivative Instruments and He58

Derivative Instruments and Hedging Activities - Fair Values of Commodity Derivatives Including Offsetting of Assets and Liabilities (Detail) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Net Amounts of Assets/ (Liabilities)	$ 315	$ 345
Net Amounts of Assets/ (Liabilities)	(321)	(183)
Gross Amounts of Recognized Assets/(Liabilities)	(368)	(207)
Gross Amounts Offset	57	46
Net Amounts of Assets/ (Liabilities)	(311)	(161)
Margin deposits	18	26
Fair Value of Derivative Assets, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	42	59
Gross Amounts Offset	(34)	(41)
Net Amounts of Assets/ (Liabilities)	8	18
Fair Value of Derivative Assets, Assets Held for Sale, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	55	51
Gross Amounts Offset	(54)	(50)
Net Amounts of Assets/ (Liabilities)	1	1
Fair Value of Derivative Assets, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	25	57
Gross Amounts Offset	(24)	(54)
Net Amounts of Assets/ (Liabilities)	1	3
Fair Value of Derivative Assets, Assets Held for Sale, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	13	15
Gross Amounts Offset	(13)	(15)
Net Amounts of Assets/ (Liabilities)	0	0
Fair Value of Derivative Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	135	182
Gross Amounts Offset	(125)	(160)
Net Amounts of Assets/ (Liabilities)	10	22
Fair Value of Derivative Liabilities, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(169)	(144)
Gross Amounts Offset	79	78
Net Amounts of Assets/ (Liabilities)	(90)	(66)
Fair Value of Derivative Liabilities, Liabilities Held For Sale, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(152)	(115)
Gross Amounts Offset	54	50
Net Amounts of Assets/ (Liabilities)	(98)	(65)
Fair Value of Derivative Liabilities, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(128)	(102)
Gross Amounts Offset	36	63
Net Amounts of Assets/ (Liabilities)	(92)	(39)
Fair Value of Derivative Liabilities, Liabilities Held For Sale, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(54)	(28)
Gross Amounts Offset	13	15
Net Amounts of Assets/ (Liabilities)	(41)	(13)
Fair Value of Derivative Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(503)	(389)
Gross Amounts Offset	182	206
Net Amounts of Assets/ (Liabilities)	(321)	(183)
CECONY
Derivatives, Fair Value [Line Items]
Net Amounts of Assets/ (Liabilities)	286	311
Gross Amounts of Recognized Assets/(Liabilities)	(217)	(125)
Gross Amounts Offset	59	48
Net Amounts of Assets/ (Liabilities)	(158)	(77)
Margin deposits	18	26
CECONY | Fair Value of Derivative Assets, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	25	40
Gross Amounts Offset	(23)	(32)
Net Amounts of Assets/ (Liabilities)	2	8
CECONY | Fair Value of Derivative Assets, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	15	48
Gross Amounts Offset	(15)	(47)
Net Amounts of Assets/ (Liabilities)	0	1
CECONY | Fair Value of Derivative Assets
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	40	88
Gross Amounts Offset	(38)	(79)
Net Amounts of Assets/ (Liabilities)	2	9
CECONY | Fair Value of Derivative Liabilities, Current
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(145)	(121)
Gross Amounts Offset	69	71
Net Amounts of Assets/ (Liabilities)	(76)	(50)
CECONY | Fair Value of Derivative Liabilities, Noncurrent
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(112)	(92)
Gross Amounts Offset	28	56
Net Amounts of Assets/ (Liabilities)	(84)	(36)
CECONY | Fair Value of Derivative Liabilities
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets/(Liabilities)	(257)	(213)
Gross Amounts Offset	97	127
Net Amounts of Assets/ (Liabilities)	$ (160)	$ (86)

Derivative Instruments and He59

Derivative Instruments and Hedging Activities - Realized and Unrealized Gains or Losses on Commodity Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	$ (4)	$ 3
Total deferred gains/(losses)	(159)	24
Net deferred gains/(losses)	(163)	27
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(113)	21
Deferred Derivative Gains, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(4)	3
Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	0	0
Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(30)	43
Recoverable energy costs
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(73)	0
Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(56)	(19)
CECONY
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(5)	3
Total deferred gains/(losses)	(145)	23
Net deferred gains/(losses)	(150)	26
CECONY | Deferred Derivative Gains, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(4)	3
CECONY | Deferred Derivative Gains, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(1)	0
CECONY | Deferred Derivative Losses, Current
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(28)	41
CECONY | Recoverable energy costs
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(66)	(2)
CECONY | Deferred Derivative Losses, Noncurrent
Pre-tax gains/(losses) deferred in accordance with accounting rules for regulated operations:
Total deferred gains/(losses)	(51)	(16)
Non Utility Operating Revenue
Pre-tax gain/(loss) recognized in income
Unrealized gain (loss) on derivatives	(1)	4
Purchased power expense
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(114)	21
Unrealized gain (loss) on derivatives	(62)	12
Gas purchased for resale
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	(10)	(42)
Non-utility revenue
Pre-tax gain/(loss) recognized in income
Total pre-tax gain/(loss) recognized in income	$ 11	$ 42

Derivative Instruments and He60

Derivative Instruments and Hedging Activities - Hedged Volume of Derivative Transactions (Detail)	3 Months Ended
	Mar. 31, 2016DTHMWhMWgal
Electric Energy Derivative
Derivatives, Fair Value [Line Items]
Electric Energy (MWH) | MWh	34,331,960
Electric Capacity Derivative
Derivatives, Fair Value [Line Items]
Capacity (MW) | MW	26,658
Natural Gas Derivative
Derivatives, Fair Value [Line Items]
Natural Gas (Dt) | DTH	43,472,324
Refined Fuels
Derivatives, Fair Value [Line Items]
Refined fuel (gallons) | gal	5,376,000
CECONY | Electric Energy Derivative
Derivatives, Fair Value [Line Items]
Electric Energy (MWH) | MWh	17,173,925
CECONY | Electric Capacity Derivative
Derivatives, Fair Value [Line Items]
Capacity (MW) | MW	12,000
CECONY | Natural Gas Derivative
Derivatives, Fair Value [Line Items]
Natural Gas (Dt) | DTH	40,280,000
CECONY | Refined Fuels
Derivatives, Fair Value [Line Items]
Refined fuel (gallons) | gal	5,376,000
Discontinued Operations, Held-for-sale | Electric Energy Derivative
Derivatives, Fair Value [Line Items]
Electric Energy (MWH) | MWh	15,495,945
Discontinued Operations, Held-for-sale | Electric Capacity Derivative
Derivatives, Fair Value [Line Items]
Capacity (MW) | MW	11,817
Discontinued Operations, Held-for-sale | Natural Gas Derivative
Derivatives, Fair Value [Line Items]
Natural Gas (Dt) | DTH	552,073

Derivative Instruments and He61

Derivative Instruments and Hedging Activities - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 209
Makeup of net credit exposure with commodity exchange brokers	112
Makeup of net credit exposure independent system operators	63
Makeup of net credit exposure with investment-grade counterparties	27
Makeup of net credit exposure non-investment grade/non-rated counterparties	7
CECONY
Investment Holdings [Line Items]
Energy supply and hedging activities credit exposure total	$ 17

Derivative Instruments and He62

Derivative Instruments and Hedging Activities - Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features (Detail) $ in Millions	Mar. 31, 2016USD ($)
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	$ 187
Collateral posted	45
Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	30
Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	192
Derivatives in net asset position additional collateral	16
Additional Collateral Required Due To Loss Of Unsecured Credit
Derivatives, Fair Value [Line Items]
Collateral posted	7
CECONY
Derivatives, Fair Value [Line Items]
Aggregate fair value – net liabilities	152
Collateral posted	44
CECONY | Downgrade One Level from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	20
CECONY | Downgrade to Below Investment Grade from Current Ratings
Derivatives, Fair Value [Line Items]
Derivatives in net liability position additional collateral	$ 148

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 315,000,000	$ 345,000,000
Derivative liabilities	321,000,000	183,000,000
Transfers between levels 1,2 and 3	0	0
CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	286,000,000	311,000,000
Transfers between levels 1,2 and 3	0	0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	174,000,000	187,000,000
Derivative liabilities	13,000,000	17,000,000
Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	160,000,000	172,000,000
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	183,000,000	200,000,000
Derivative liabilities	421,000,000	286,000,000
Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	108,000,000	114,000,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	8,000,000	14,000,000
Derivative liabilities	12,000,000	8,000,000
Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	27,000,000	47,000,000
Derivative liabilities	182,000,000	105,000,000
Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	20,000,000	35,000,000
Derivative liabilities	160,000,000	86,000,000
Commodity | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	2,000,000
Derivative liabilities	12,000,000	16,000,000
Commodity | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	1,000,000
Derivative liabilities	12,000,000	14,000,000
Commodity | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	19,000,000	25,000,000
Derivative liabilities	241,000,000	153,000,000
Commodity | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,000,000	9,000,000
Derivative liabilities	209,000,000	129,000,000
Commodity | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6,000,000	13,000,000
Derivative liabilities	2,000,000	1,000,000
Commodity | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,000,000	8,000,000
Derivative liabilities	0	0
Commodity Contract, Held For Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,000,000	1,000,000
Derivative liabilities	139,000,000	78,000,000
Commodity Contract, Held For Sale | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	1,000,000	1,000,000
Commodity Contract, Held For Sale | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	51,000,000	63,000,000
Derivative liabilities	180,000,000	133,000,000
Commodity Contract, Held For Sale | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,000,000	1,000,000
Derivative liabilities	10,000,000	7,000,000
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	287,000,000	297,000,000
Other | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	266,000,000	276,000,000
Other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	174,000,000	185,000,000
Other | Level 1 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	160,000,000	171,000,000
Other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	113,000,000	112,000,000
Other | Level 2 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	106,000,000	105,000,000
Other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Other | Level 3 | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Netting Adjustments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(50,000,000)	(56,000,000)
Derivative liabilities	(125,000,000)	(128,000,000)
Netting Adjustments | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2,000,000	7,000,000
Derivative liabilities	(73,000,000)	(65,000,000)
Netting Adjustments | Commodity | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	16,000,000	17,000,000
Derivative liabilities	(61,000,000)	(57,000,000)
Netting Adjustments | Commodity Contract, Held For Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(52,000,000)	(63,000,000)
Derivative liabilities	(52,000,000)	(63,000,000)
Netting Adjustments | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Netting Adjustments | Other | CECONY
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Commodity Derivatives (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)$ / kW-month$ / MWh
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Transmission Congestion Contracts/Financial Transmission Rights
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
Minimum | Discount to Adjust Auction Prices for Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	40.80%
Minimum | Discount to Adjust Auction Prices for Historical Monthly Realized Settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	1.60%
Minimum | Inter-Zonal Forward Price Curves Adjusted for Historical Zonal Losses
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	(5.10)
Minimum | Forward Energy Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH/Dt) | $ / MWh	15.32
Minimum | Forward Capacity Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH/Dt) | $ / kW-month	0.58
Maximum | Discount to Adjust Auction Prices for Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	62.10%
Maximum | Discount to Adjust Auction Prices for Historical Monthly Realized Settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	82.20%
Maximum | Inter-Zonal Forward Price Curves Adjusted for Historical Zonal Losses
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per kW-month) | $ / MWh	2.25
Maximum | Forward Energy Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH/Dt) | $ / MWh	74.99
Maximum | Forward Capacity Prices
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range (dollar per MWH/Dt) | $ / kW-month	8.10
Level 3
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ (4)
Level 3 | Electricity
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	(7)
Level 3 | Transmission Congestion Contracts/Financial Transmission Rights
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 3
CECONY | Transmission Congestion Contracts
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Valuation Techniques	Discounted Cash Flow
CECONY | Minimum | Discount to Adjust Auction Prices for Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	40.80%
CECONY | Minimum | Discount to Adjust Auction Prices for Historical Monthly Realized Settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	1.60%
CECONY | Maximum | Discount to Adjust Auction Prices for Inter-Zonal Forward Price Curves
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	62.10%
CECONY | Maximum | Discount to Adjust Auction Prices for Historical Monthly Realized Settlements
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Unobservable Inputs Range in percentage	82.20%
CECONY | Level 3 | Transmission Congestion Contracts
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value of commodity derivatives | $	$ 2

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 6	$ 20
Included in earnings	(7)	(10)
Included in regulatory assets and liabilities	(3)	0
Purchases	0	3
Settlements	0	(2)
Ending balance	(4)	11
CECONY
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	8	13
Included in earnings	(1)	(2)
Included in regulatory assets and liabilities	(4)	0
Purchases	0	2
Settlements	(1)	(1)
Ending balance	$ 2	$ 12

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Purchased power expense
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, assets measured on recurring basis, change in unrealized gain (loss)	$ (4)	$ (5)
Competitive energy businesses
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Gain (loss) on Level 3 energy derivative liabilities	$ (6)	$ (8)

Variable Interest Entities - Ad

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

Variable Interest Entities - Su

Variable Interest Entities - Summary of VIEs (Detail)	3 Months Ended
	Mar. 31, 2016USD ($)MW
Pilesgrove | Minimum | Solar Renewable Energy Credit Hedge
Variable Interest Entity [Line Items]
Renewable Energy Credit	3 years
Pilesgrove | Maximum | Solar Renewable Energy Credit Hedge
Variable Interest Entity [Line Items]
Renewable Energy Credit	4 years
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure
Variable Interest Entity [Line Items]
Percentage of variable interests	50.00%
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 3 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	128
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 183,000,000
Variable Interest Entity, Not Primary Beneficiary | Panoche Valley | California
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	124
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,015
Maximum exposure to loss	$ 133,000,000
Variable Interest Entity, Not Primary Beneficiary | Mesquite Solar 1 | Arizona
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	83
Power Purchase Agreement Term (in Years)	20 years
Year of Initial Investment	2,013
Maximum exposure to loss	$ 99,000,000
Variable Interest Entity, Not Primary Beneficiary | Copper Mountain Solar 2 | Nevada
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	75
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,013
Maximum exposure to loss	$ 82,000,000
Variable Interest Entity, Not Primary Beneficiary | California Solar | California
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	55
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,012
Maximum exposure to loss	$ 65,000,000
Variable Interest Entity, Not Primary Beneficiary | Broken Bow II | Nebraska
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	38
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 54,000,000
Variable Interest Entity, Not Primary Beneficiary | Pilesgrove | New Jersey
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	9
Year of Initial Investment	2,010
Maximum exposure to loss	$ 26,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4
Variable Interest Entity [Line Items]
Percentage of variable interests	80.00%
VIEs, noncontrolling interest	$ 8,000,000
Variable Interest Entity, Primary Beneficiary | Texas Solar 4 | Texas
Variable Interest Entity [Line Items]
Generating Capacity (MWs AC) | MW	32
Power Purchase Agreement Term (in Years)	25 years
Year of Initial Investment	2,014
Maximum exposure to loss	$ 15,000,000

Assets Held For Sale (Details)

Assets Held For Sale (Details) - USD ($)	Sep. 30, 2015	Oct. 31, 2015	Jun. 30, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and temporary cash investments				$ 2,000,000		$ 0
Total current assets				166,000,000	$ 157,000,000
Non-utility property, less accumulated depreciation of $13				859,000,000	832,000,000
Total current liabilities				150,000,000	$ 89,000,000
Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets to be disposed of			$ 0
Cash and temporary cash investments				7,000,000
Accounts receivable less allowance for uncollectible accounts of $2				67,000,000
Accrued unbilled revenue				68,000,000
Other assets				3,000,000
Total current assets				145,000,000
Utility plant, less accumulated depreciation of $6				14,000,000
Non-utility property, less accumulated depreciation of $13				3,000,000
Non-utility property construction work in progress				1,000,000
Regulatory assets				3,000,000
Total assets held for sale				166,000,000
Fair value of derivative liabilities				98,000,000
Accounts payable				3,000,000
Other				5,000,000
Total current liabilities				106,000,000
Fair value of derivative liabilities				41,000,000
Long-term debt				3,000,000
Total liabilities held for sale				150,000,000
Allowance for uncollectible accounts				2,000,000
Depreciation, utility plant				6,000,000
Depreciation, non-utility property				13,000,000
Retail Electric Supply Business | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and temporary cash investments				0
Accounts receivable less allowance for uncollectible accounts of $2				67,000,000
Accrued unbilled revenue				67,000,000
Other assets				2,000,000
Total current assets				136,000,000
Utility plant, less accumulated depreciation of $6				0
Non-utility property, less accumulated depreciation of $13				3,000,000
Non-utility property construction work in progress				1,000,000
Regulatory assets				0
Total assets held for sale				140,000,000
Fair value of derivative liabilities				98,000,000
Accounts payable				3,000,000
Other				3,000,000
Total current liabilities				104,000,000
Fair value of derivative liabilities				41,000,000
Long-term debt				0
Total liabilities held for sale				145,000,000
Pike | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets to be disposed of	$ 5,000,000
Proceeds from divestiture of business		$ 16,000,000
Impairment of long-lived assets to be disposed of, net of taxes	$ 3,000,000
Cash and temporary cash investments				7,000,000
Accounts receivable less allowance for uncollectible accounts of $2				0
Accrued unbilled revenue				1,000,000
Other assets				1,000,000
Total current assets				9,000,000
Utility plant, less accumulated depreciation of $6				14,000,000
Non-utility property, less accumulated depreciation of $13				0
Non-utility property construction work in progress				0
Regulatory assets				3,000,000
Total assets held for sale				26,000,000
Fair value of derivative liabilities				0
Accounts payable				0
Other				2,000,000
Total current liabilities				2,000,000
Fair value of derivative liabilities				0
Long-term debt				3,000,000
Total liabilities held for sale				$ 5,000,000

Acquisitions, Investments and70

Acquisitions, Investments and Dispositions (Details)	1 Months Ended		3 Months Ended
	Apr. 30, 2016USD ($)	Jan. 31, 2016USD ($)MW	Dec. 31, 2018USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Guarantee obligations maximum exposure				$ 2,705,000,000	$ 2,856,000,000
Ownership interest, percentage						45.70%
Construction work in progress				1,115,000,000	$ 1,003,000,000
Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments		$ 18,000,000
Equity method ownership (percent)		12.50%
Texas Solar 7 | Texas
Schedule of Equity Method Investments [Line Items]
Generating capacity | MW		106
Payments to acquire business		$ 227,000,000
Non-utility construction work in progress		218,000,000
Other receivables		9,000,000
Electric | Texas Solar 7 | Texas
Schedule of Equity Method Investments [Line Items]
Consideration transferred		375,000,000
Subsequent Event | Stagecoach Gas Services LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments	$ 975,000,000
Equity method ownership (percent)	50.00%
Electric Transmission Project | Discontinued Operations, Disposed of by Sale
Schedule of Equity Method Investments [Line Items]
Payment for leases		$ 7,600,000
Construction work in progress				96,000,000
Financial and Performance Guarantee, Other
Schedule of Equity Method Investments [Line Items]
Guarantee obligations maximum exposure				$ 75,000,000
Financial and Performance Guarantee, Other | Subsequent Event
Schedule of Equity Method Investments [Line Items]
Guarantee obligations maximum exposure	$ 946,000,000
Scenario, Forecast | Gas | Minimum | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments			$ 3,000,000,000
Scenario, Forecast | Gas | Maximum | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments			$ 3,500,000,000
CET Electric
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage		45.70%