Income Tax (Tables)

12 Months Ended

Dec. 31, 2016

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax

The components of income tax are as follows:

	Con Edison			CECONY
(Millions of Dollars)	2016	2015	2014	2016	2015	2014
State
Current	$(42)	$38	$59	$(1)	$48	$66
Deferred	188	93	61	114	82	65
Federal
Current	(43)	(86)	(9)	59	77	158
Deferred	604	569	463	435	372	271
Amortization of investment tax credits	(9)	(9)	(6)	(4)	(5)	(5)
Total income tax expense	$698	$605	$568	$603	$574	$555

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)	2016	2015	2016	2015
Deferred tax liabilities:
Property basis differences	$9,446	$8,614	$8,620	$7,922
Regulatory assets:
Unrecognized pension and other postretirement costs	1,162	1,562	1,104	1,490
Future income tax	986	947	940	899
Environmental remediation costs	333	365	287	322
Deferred storm costs	23	75	1	45
Other regulatory assets	371	367	321	308
Equity investments	363	295	—	—
Total deferred tax liabilities	$12,684	$12,225	$11,273	$10,986
Deferred tax assets:
Accrued pension and other postretirement costs	$581	$982	$467	$857
Regulatory liabilities	822	836	728	752
Superfund and other environmental costs	304	308	265	268
Asset retirement obligations	99	97	92	94
Loss carryforwards	59	29	—	—
Tax credits carryforward	498	258	—	1
Valuation allowance	(16)	(15)	—	—
Other	303	362	312	292
Total deferred tax assets	2,650	2,857	1,864	2,264
Net deferred tax liabilities	$10,034	$9,368	$9,409	$8,722
Unamortized investment tax credits	171	169	41	33
Net deferred tax liabilities and unamortized investment tax credits	$10,205	$9,537	$9,450	$8,755

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)	2016		2015		2014		2016		2015		2014
STATUTORY TAX RATE
Federal	35	%	35	%	35	%	35	%	35	%	35	%
Changes in computed taxes resulting from:
State income tax	4		5		5		4		5		5
Cost of removal	(1	)	(5	)	(5	)	(1	)	(5	)	(5	)
Renewable energy credits	(1	)	(1	)	—		—		—		—
Research and development credits	(1	)	—		—		(1	)	—		—
Other	—		—		(1	)	(1	)	—		(1	)
Effective tax rate	36	%	34	%	34	%	36	%	35	%	34	%

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)	2016	2015	2014	2016	2015		2014
Balance at January 1,	$34	$34	$9	$2		$2		$—
Additions based on tax positions related to the current year	2	—	—	2	—		—
Additions based on tax positions of prior years	19	1	27	19	—		2
Reductions for tax positions of prior years	(13)	—	(2)	(2)	—		—
Reductions from expiration of statute of limitations	—	(1)	—	—	—		—
Settlements	—	—	—	—	—		—
Balance at December 31,	$42	$34	$34	$21	$2		$2