Commitments and Contingencies - Schedule of Long-term Commitments (Detail) $ in Millions	Mar. 31, 2024 USD ($)
Other Commitments [Line Items]
2024	$ 883
2025	328
2026	230
2027	164
2028	121
Thereafter	948
Total future minimum payments	2,674
Transportation [Member]
Other Commitments [Line Items]
2024	103
2025	131
2026	130
2027	130
2028	102
Thereafter	840
Total future minimum payments	1,436
Capital Projects [Member]
Other Commitments [Line Items]
2024	601
2025	98
2026	58
2027	6
2028	0
Thereafter	0
Total future minimum payments	763
Fuel and Gas Supply [Member]
Other Commitments [Line Items]
2024	162
2025	69
2026	17
2027	4
2028	1
Thereafter	0
Total future minimum payments	253
Long-term Service Agreements [Member]
Other Commitments [Line Items]
2024	9
2025	22
2026	23
2027	22
2028	17
Thereafter	33
Total future minimum payments	126
Other [Member]
Other Commitments [Line Items]
2024	8
2025	8
2026	2
2027	2
2028	1
Thereafter	75
Total future minimum payments	$ 96

Amount of contractual obligation, including, but not limited to, long-term debt, lease obligation, purchase obligation, and other commitments.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-3

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+ References

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+ References

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Amount of contractual obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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+ References

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Amount of contractual obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of contractual obligation to be paid in remainder of current fiscal year.

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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.

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