Pension, OPEB and Savings Plans (Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2022 USD ($)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Payments Expected Next Twelve Months	$ 424
Payments Expected Year Two	400
Payments Expected Year Three	405
Payments Expected Year Four	411
Payments Expected Year Five	418
Payments Expected Thereafter	2,124
Total Estimated Future Benefit Payments	4,182
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Payments Expected Next Twelve Months	77
Payments Expected Year Two	75
Payments Expected Year Three	74
Payments Expected Year Four	72
Payments Expected Year Five	70
Payments Expected Thereafter	309
Total Estimated Future Benefit Payments	677
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Payments Expected Next Twelve Months	12
Payments Expected Year Two	14
Payments Expected Year Three	17
Payments Expected Year Four	19
Payments Expected Year Five	22
Payments Expected Thereafter	149
Total Estimated Future Benefit Payments	233
Long Island Electric Utility Servco LLC Pension and OPEB [Member] | Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Payments Expected Next Twelve Months	10
Payments Expected Year Two	12
Payments Expected Year Three	14
Payments Expected Year Four	15
Payments Expected Year Five	17
Payments Expected Thereafter	112
Total Estimated Future Benefit Payments	$ 180