Income Tax	6 Months Ended
Income Tax	Jun. 30, 2016
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense increased to $124 million for the three months ended June 30, 2016 from $101 million for the three months ended June 30, 2015. Con Edison's effective tax rate for the three months ended June 30, 2016 and 2015 was 35 percent and 32 percent, respectively. For the three months ended June 30, 2016, Con Edison recorded lower tax benefits for plant-related flow through items, partially offset by increased tax benefits as a result of higher injuries and damages payments and higher renewable energy tax credits. CECONY’s income tax expense decreased to $84 million for the three months ended June 30, 2016 from $101 million for the three months ended June 30, 2015. CECONY's effective tax rate for the three months ended June 30, 2016 and 2015 was 34 percent and 32 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, partially offset by increased tax benefits as a result of higher injuries and damages payments. Con Edison’s income tax expense decreased to $288 million for the six months ended June 30, 2016 from $300 million for the six months ended June 30, 2015. Con Edison's effective tax rate for the six months ended June 30, 2016 and 2015 was 35 percent and 34 percent, respectively. For the six months ended June 30, 2016, Con Edison recorded income tax benefits for research and development tax credits and higher renewable energy tax credits, which were primarily offset by a decrease in tax benefits for plant-related flow through items. CECONY’s income tax expense decreased to $264 million for the six months ended June 30, 2016 from $293 million for the six months ended June 30, 2015. CECONY's effective tax rate for the six months ended June 30, 2016 and 2015 was 36 percent and 34 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, 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 and recover $10 million of income tax. General business tax credits that became available as a result of the net operating loss carryback, as well as the remaining 2016 net operating loss will be carried forward to future tax years. A deferred tax asset for these tax attribute carryforwards was recorded, and no valuation allowance has been provided, as it is more likely than not that the deferred tax asset will be realized. Uncertain Tax Positions At June 30, 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 and six months ended June 30, 2016, the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At June 30, 2016 and December 31, 2015, the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.
CECONY
Income Tax Examination [Line Items]
Income Tax	Income Tax Con Edison’s income tax expense increased to $124 million for the three months ended June 30, 2016 from $101 million for the three months ended June 30, 2015. Con Edison's effective tax rate for the three months ended June 30, 2016 and 2015 was 35 percent and 32 percent, respectively. For the three months ended June 30, 2016, Con Edison recorded lower tax benefits for plant-related flow through items, partially offset by increased tax benefits as a result of higher injuries and damages payments and higher renewable energy tax credits. CECONY’s income tax expense decreased to $84 million for the three months ended June 30, 2016 from $101 million for the three months ended June 30, 2015. CECONY's effective tax rate for the three months ended June 30, 2016 and 2015 was 34 percent and 32 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, partially offset by increased tax benefits as a result of higher injuries and damages payments. Con Edison’s income tax expense decreased to $288 million for the six months ended June 30, 2016 from $300 million for the six months ended June 30, 2015. Con Edison's effective tax rate for the six months ended June 30, 2016 and 2015 was 35 percent and 34 percent, respectively. For the six months ended June 30, 2016, Con Edison recorded income tax benefits for research and development tax credits and higher renewable energy tax credits, which were primarily offset by a decrease in tax benefits for plant-related flow through items. CECONY’s income tax expense decreased to $264 million for the six months ended June 30, 2016 from $293 million for the six months ended June 30, 2015. CECONY's effective tax rate for the six months ended June 30, 2016 and 2015 was 36 percent and 34 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, 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 and recover $10 million of income tax. General business tax credits that became available as a result of the net operating loss carryback, as well as the remaining 2016 net operating loss will be carried forward to future tax years. A deferred tax asset for these tax attribute carryforwards was recorded, and no valuation allowance has been provided, as it is more likely than not that the deferred tax asset will be realized. Uncertain Tax Positions At June 30, 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 and six months ended June 30, 2016, the Companies recognized an immaterial amount of interest expense and no penalties for uncertain tax positions in their consolidated income statements. At June 30, 2016 and December 31, 2015, the Companies recognized an immaterial amount of accrued interest on their consolidated balance sheets.