Income Tax (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax

The components of income tax are as follows:

	Con Edison			CECONY
(Millions of Dollars)	2019	2018	2017	2019	2018	2017
State
Current	$(12)	$(10)	$(2)	$22	$6	$37
Deferred	96	107	103	68	82	75
Federal
Current	—	3	(11)	185	(34)	73
Deferred	219	310	391	63	275	504
Amortization of investment tax credits	(7)	(9)	(9)	(3)	(3)	(4)
Total income tax expense	$296	$401	$472	$335	$326	$685

Schedule of Differences on Deferred Tax Assets and Liabilities

The tax effects of temporary differences, which gave rise to deferred tax assets and liabilities, are as follows:

	Con Edison		CECONY
(Millions of Dollars)	2019	2018	2019	2018
Deferred tax liabilities:
Property basis differences	$7,699	$7,402	$6,640	$6,446
Regulatory assets:
Unrecognized pension and other postretirement costs	712	627	674	591
Environmental remediation costs	205	227	181	200
Deferred storm costs	22	21	—	—
Other regulatory assets	376	273	355	252
Operating lease right-of-use asset	231	—	169	—
Equity investments	104	102	—	—
Total deferred tax liabilities	$9,349	$8,652	$8,019	$7,489
Deferred tax assets:
Accrued pension and other postretirement costs	$291	$248	$222	$180
Regulatory liabilities:
Future income tax	678	702	638	662
Other regulatory liabilities	702	632	622	554
Superfund and other environmental costs	206	218	183	194
Asset retirement obligations	135	114	102	82
Operating lease liabilities	231	—	170	—
Loss carryforwards	108	229	—	—
Tax credits carryforward	896	817	—	—
Valuation allowance	(40)	(33)	—	—
Other	56	53	103	102
Total deferred tax assets	3,263	2,980	2,040	1,774
Net deferred tax liabilities	$6,086	$5,672	$5,979	$5,715
Unamortized investment tax credits	141	148	21	24
Net deferred tax liabilities and unamortized investment tax credits	$6,227	$5,820	$6,000	$5,739

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)	2019		2018		2017		2019		2018		2017
STATUTORY TAX RATE
Federal	21	%	21	%	35	%	21	%	21	%	35	%
Changes in computed taxes resulting from:
State income tax	4		4		4		5		5		4
Taxes attributable to noncontrolling interests	(1	)	—		—		—		—		—
Cost of removal	1		1		1		1		1		1
Other plant-related items	(1	)	(1	)	(1	)	(1	)	(1	)	(1	)
TCJA deferred tax re-measurement	—		2		(13	)	—		—		—
Amortization of excess deferred federal income taxes	(4	)	(3	)	—		(4	)	(3	)	—
Renewable energy credits	(2	)	(1	)	(1	)	—		—		—
Research and development credits	(1	)	—		—		(1	)	(1	)	—
Other	—		—		(2	)	—		(1	)	(1	)
Effective tax rate	17	%	23	%	23	%	21	%	21	%	38	%

Summary of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amounts of unrecognized tax benefits for Con Edison and CECONY follows:

	Con Edison			CECONY
(Millions of Dollars)	2019	2018	2017	2019	2018	2017
Balance at January 1,	$6	$12	$42	$4	$5	$21
Additions based on tax positions related to the current year	1	2	1	1	2	1
Additions based on tax positions of prior years	10	1	1	—	1	1
Reductions for tax positions of prior years	(2)	(2)	(24)	(1)	(1)	(18)
Reductions from expiration of statute of limitations	—	(4)	(2)	—	—	—
Settlements	(2)	(3)	(6)	(2)	(3)	—
Balance at December 31,	$13	$6	$12	$2	$4	$5