Pension And Other Postretirement Benefit Plans (Assumptions Used To Compute Net Periodic Benefit Cost And Benefit Obligations) (Details)	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates: Benefit cost for plan year	5.00%	3.70%	3.30%
Discount rates: Benefit obligation at end of plan year	5.27%	5.00%	3.70%
Expected long-term return on plan assets: Benefit cost for plan year	6.50%	5.50%	5.50%
Salary scale: Benefit cost for plan year	4.00%	4.00%	4.00%
Salary scale: Benefit obligation at end of plan year	4.00%	4.00%	4.00%
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rates: Benefit cost for plan year	4.90%	3.60%	2.90%
Discount rates: Benefit obligation at end of plan year	5.17%	4.90%	3.60%
Expected long-term return on plan assets: Benefit cost for plan year	3.00%	3.00%	3.00%
Salary scale: Benefit cost for plan year	4.00%	4.00%	4.00%
Salary scale: Benefit obligation at end of plan year	4.00%	4.00%	4.00%
Healthcare cost trend rate	6.97%	6.97%	6.17%

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

+ References

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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
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-8

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related 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

Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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