annual interest crediting rates

No definition available.

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- Definition

An assumption as to the rate of return on plan assets for the next fiscal year reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

No definition available.

+ Details

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- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

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No definition available.

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of net periodic benefit cost (credit) for defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition

The amount of operating expenses for the period that are associated with the utility's normal revenue producing operation; including selling, general, and administrative expenses, costs incurred for routine plant repairs and maintenance, and operations.

+ References

No definition available.

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Benefit Plans and Other Postretirement Benefits, Pension Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Operating and maintenance expenses		$ 223,000,000	$ 198,000,000	$ 191,000,000
Target Pension Asset Allocations [Abstract]
annual interest crediting rates [Domain]		4.86	1.96	1.78
annual interest crediting rates [Domain]		4.86	1.96	1.78
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Operating and maintenance expenses			1,000,000
Pension Benefits [Abstract]
Total benefit obligation		112,000,000	141,000,000	154,000,000
Net benefit cost recognized for financial reporting		$ 8,000,000	$ 8,000,000	$ 13,000,000
Expected average long-term rate of return on assets (as a percent)		6.60%	6.60%	7.10%
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		100.00%	100.00%
Pension Plan [Member] \| Domestic and international equity securities
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		33.00%	33.00%
Pension Plan [Member] \| Long-duration fixed income and interest rate swap securities
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		38.00%	37.00%
Pension Plan [Member] \| Short-to-intermediate fixed income securities
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		9.00%	11.00%
Pension Plan [Member] \| Alternative investments
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		18.00%	17.00%
Pension Plan [Member] \| Cash
Target Pension Asset Allocations [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		2.00%	2.00%
Forecast [Member] \| Pension Plan [Member]
Pension Benefits [Abstract]
Expected average long-term rate of return on assets for next fiscal year (as a percent)	7.25%
Parent Company [Member] \| Supplemental Executive Retirement Plan (SERP) and Nonqualified Pension Plan
Pension Benefits [Abstract]
Total benefit obligation		$ 11,000,000	$ 43,000,000
Net benefit cost recognized for financial reporting		$ 17,000,000	$ 4,000,000