Income Tax (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Income Tax Reconciliation

Reconciliation of the difference between income tax expense and the amount computed by applying the prevailing statutory income tax rate to income before income taxes is as follows:

	Con Edison				CECONY
(% of Pre-tax income)	2018		2017		2018		2017
STATUTORY TAX RATE
Federal	21	%	35	%	21	%	35	%
Changes in computed taxes resulting from:
State income tax	4		4		5		4
Cost of removal	1		1		1		1
Other plant-related items	—		—		(1	)	(1	)
Change in deferred taxes	—		(1	)	—		—
Renewable energy credits	(1	)	(1	)	—		—
Amortization of excess deferred federal income taxes	(3	)	—		(3	)	—
Other	(1	)	(1	)	—		—
Effective tax rate	21	%	37	%	23	%	39	%