Consolidated Balance Sheet (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
NON-UTILITY PLANT
Non-utility property	$ 102	$ 89
Construction work in progress	48	39
NET PLANT	25,734	25,093
OTHER NONCURRENT ASSETS
Goodwill	429	429
Intangible assets, less accumulated amortization of $4 and $3 in 2012 and 2011, respectively	3	3
Regulatory assets	9,078	9,337
Other deferred charges and noncurrent assets	252	259
TOTAL OTHER NONCURRENT ASSETS	9,762	10,028
TOTAL ASSETS	40,049	39,214
CURRENT ASSETS
Cash and temporary cash investments	1,381	648
Accounts receivable - customers	1,034	1,123
Other receivables	228	303
Accrued unbilled revenue	493	474
Fuel oil, gas in storage, materials and supplies, at average cost	337	356
Prepayments	151	145
Regulatory assets	127	164
Deferred tax assets - current	136	266
Other current assets	215	159
TOTAL CURRENT ASSETS	4,102	3,638
INVESTMENTS	451	455
UTILITY PLANT, AT ORIGINAL COST
General	2,093	1,944
TOTAL	30,799	29,775
Less: Accumulated depreciation	6,263	6,051
Net	24,536	23,724
Construction work in progress	1,048	1,241
NET UTILITY PLANT	25,584	24,965
CURRENT LIABILITIES
Long-term debt due within one year	1,231	530
Notes payable	800
Accounts payable	813	955
Customer deposits	308	303
Accrued taxes	154	188
Accrued interest	179	160
Accrued wages	91	91
Fair value of derivative liabilities	110	169
Regulatory liabilities	233	118
Other current liabilities	461	473
TOTAL CURRENT LIABILITIES	4,380	2,987
NONCURRENT LIABILITIES
Obligations under capital leases	2	2
Provision for injuries and damages	158	181
Pensions and retiree benefits	4,385	4,835
Superfund and other environmental costs	539	489
Asset retirement obligations	147	145
Fair value of derivative liabilities	51	48
Other noncurrent liabilities	119	131
TOTAL NONCURRENT LIABILITIES	5,401	5,831
DEFERRED CREDITS AND REGULATORY LIABILITIES
Deferred income taxes and investment tax credits	7,743	7,563
Regulatory liabilities	1,029	977
Other deferred credits	77	64
TOTAL DEFERRED CREDITS AND REGULATORY LIABILITIES	8,849	8,604
LONG-TERM DEBT	9,840	10,143
SHAREHOLDER'S EQUITY
Common shareholder's equity (See Statement of Common Shareholder's Equity)	11,579	11,436
Preferred stock of subsidiary		213
TOTAL SHAREHOLDER'S EQUITY	11,579	11,649
TOTAL LIABILITIES AND SHAREHOLDER'S EQUITY	40,049	39,214
CECONY
NON-UTILITY PLANT
Non-utility property	5	6
NET PLANT	24,089	23,502
OTHER NONCURRENT ASSETS
Regulatory assets	8,457	8,661
Other deferred charges and noncurrent assets	214	217
TOTAL OTHER NONCURRENT ASSETS	8,671	8,878
TOTAL ASSETS	36,109	35,218
CURRENT ASSETS
Cash and temporary cash investments	1,033	372
Accounts receivable - customers	914	977
Other receivables	104	102
Accrued unbilled revenue	389	366
Accounts receivable from affiliated companies	46	54
Fuel oil, gas in storage, materials and supplies, at average cost	290	308
Prepayments	80	85
Regulatory assets	104	140
Deferred tax assets - current	81	157
Other current assets	115	100
TOTAL CURRENT ASSETS	3,156	2,661
INVESTMENTS	193	177
UTILITY PLANT, AT ORIGINAL COST
General	1,933	1,785
TOTAL	28,820	27,854
Less: Accumulated depreciation	5,718	5,523
Net	23,102	22,331
Construction work in progress	982	1,165
NET UTILITY PLANT	24,084	23,496
CURRENT LIABILITIES
Long-term debt due within one year	1,225	525
Notes payable	800
Accounts payable	666	774
Accounts payable to affiliated companies	20	16
Customer deposits	296	290
Accrued taxes	19	32
Accrued taxes to affiliated companies	136	126
Accrued interest	140	133
Accrued wages	83	81
Fair value of derivative liabilities	62	98
Regulatory liabilities	202	79
Other current liabilities	393	396
TOTAL CURRENT LIABILITIES	4,042	2,550
NONCURRENT LIABILITIES
Obligations under capital leases	2	2
Provision for injuries and damages	151	173
Pensions and retiree benefits	3,917	4,337
Superfund and other environmental costs	423	373
Asset retirement obligations	147	145
Fair value of derivative liabilities	22	24
Other noncurrent liabilities	111	120
TOTAL NONCURRENT LIABILITIES	4,773	5,174
DEFERRED CREDITS AND REGULATORY LIABILITIES
Deferred income taxes and investment tax credits	7,081	6,921
Regulatory liabilities	906	861
Other deferred credits	74	61
TOTAL DEFERRED CREDITS AND REGULATORY LIABILITIES	8,061	7,843
LONG-TERM DEBT	8,919	9,220
SHAREHOLDER'S EQUITY
Common shareholder's equity (See Statement of Common Shareholder's Equity)	10,314	10,218
Preferred stock of subsidiary		213
TOTAL SHAREHOLDER'S EQUITY	10,314	10,431
TOTAL LIABILITIES AND SHAREHOLDER'S EQUITY	36,109	35,218
Electric Transmission [Member]
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	21,757	21,114
Electric Transmission [Member] | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	20,492	19,886
Gas Transmission [Member]
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	4,930	4,734
Gas Transmission [Member] | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	4,376	4,200
Steam Plant [Member]
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	2,019	1,983
Steam Plant [Member] | CECONY
UTILITY PLANT, AT ORIGINAL COST
Utility plant, at original cost	$ 2,019	$ 1,983