Pension, OPEB and Savings Plans (Fair Value Measurements And The Levels Of Inputs Used In Determining Fair Values) (Details) - USD ($) $ in Millions		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	$ 4,578		$ 5,331
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4,140		4,911		$ 6,906
Net receivables excluded from Fair Value		2		7
Cash and foreign currency excluded from Fair Value				2
Nuclear Decommissioning Trust (NDT) Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash and foreign currency excluded from Fair Value		1		2
Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	39		36
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	748		1,231
Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	1,376		1,346
Commingled Equities at NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[5]	745		965
Private Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2		3
US Treasury Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	1,299		1,351
Commingled Debt [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	4		4
Subtotal before Measured at Net Asset Value Practical Expedient [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	3,466		3,968
Real Estate Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[7]	365		395
Quoted Market Prices for Identical Assets (Level 1) [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	39		36
Quoted Market Prices for Identical Assets (Level 1) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	748		1,231
Quoted Market Prices for Identical Assets (Level 1) [Member] | Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	0		0
Quoted Market Prices for Identical Assets (Level 1) [Member] | US Treasury Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	0		0
Quoted Market Prices for Identical Assets (Level 1) [Member] | Commingled Debt [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	4		4
Quoted Market Prices for Identical Assets (Level 1) [Member] | Subtotal before Measured at Net Asset Value Practical Expedient [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	791		1,271
Significant Other Observable Inputs (Level 2) [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	0		0
Significant Other Observable Inputs (Level 2) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	0		0
Significant Other Observable Inputs (Level 2) [Member] | Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	1,376		1,346
Significant Other Observable Inputs (Level 2) [Member] | US Treasury Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	1,299		1,351
Significant Other Observable Inputs (Level 2) [Member] | Commingled Debt [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	0		0
Significant Other Observable Inputs (Level 2) [Member] | Subtotal before Measured at Net Asset Value Practical Expedient [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[6]	2,675		2,697
Long Island Electric Utility Servco LLC Pension and OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		433		370
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		433		370		$ 422
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2		1
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		32	[8]	25
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[9]	294		251
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[9]	105		93
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		34		26
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member] | Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2		1
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		32	[8]	25	[9]
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member] | Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	[9]	0
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Quoted Market Prices for Identical Assets (Level 1) [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[9]	0		0
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		399		344
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Significant Other Observable Inputs (Level 2) [Member] | Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0		0
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Significant Other Observable Inputs (Level 2) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	[8]	0	[9]
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commingled Equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		294	[9]	251
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[9]	$ 105		$ 93

[1] Excludes net receivables of $2 million and $7 million as of December 31, 2023 and 2022, respectively, which consist of interest, dividends and receivables and payables related to pending securities sales and purchases. In addition, the table excludes cash and foreign currency of $2 million as of December 31, 2022.

[2] The Collective Investment Fund publishes a daily net asset value (NAV) which participants may use for daily redemptions without restrictions (Level 1).

[3] Common stocks are measured using observable data in active markets and considered Level 1.

[4] Commingled Funds that publish daily NAV but with certain near-term redemption restrictions which prevent redemption at the published daily NAV are classified as Level 2.

[5] Certain commingled equity funds are not included in the fair value hierarchy as they are measured at fair value using the NAV per share (or its equivalent) practical expedient. These funds do not meet the definition of readily determinable fair value due to the frequency of publishing NAV (monthly). The objectives of these funds are mainly tracking the S&P Index or achieving long-term growth through investment in foreign equity securities and the Morgan Stanley Capital International Index.

[6] Debt securities include mainly U.S. Treasury obligations. These investments are valued using an evaluated pricing approach that varies by asset class and reflects observable market information such as the most recent exchange price or quoted bid for similar securities. Market-based standard inputs typically include benchmark yields, reported trades, broker/dealer quotes and issuer spreads or the most recent quotes for similar securities which are a Level 2 measure.

[7] The unlisted real estate fund invests in office, apartment, industrial and retail space. The fund is valued using the NAV per unit of funds. The investment value of the real estate properties is determined on a quarterly basis by independent market appraisers engaged by the board of directors of the fund. The ability to redeem funds is subject to the availability of cash arising from net investment income, allocations and the sale of investments in the normal course of business. The fund’s NAV is published quarterly. In addition, redemptions require one quarter advance notice prior to redemption and are fulfilled quarterly. The fund, therefore, does not meet the definition of readily determinable fair value. The purpose of the fund is to acquire, own, hold for investment and ultimately dispose of investments in real estate and real estate-related assets with the intention of achieving current income, capital appreciation or both.

[8] Common stocks are measured using observable data in active markets and considered Level 1.

[9] Investments in commingled equity and bond funds have a readily determinable fair value as they publish a daily NAV available to investors which is the basis for current transactions and contain certain redemption restrictions requiring advance notice of one to two days for withdrawals (Level 2).