Commitments and Contingencies - Schedule of Long-term Commitments (Detail) $ in Millions	Jun. 30, 2021 USD ($)
Other Commitments [Line Items]
2021	$ 663
2022	406
2023	316
2024	234
2025	211
Thereafter	2,128
Total future minimum payments	3,958
Purchased Power [Member]
Other Commitments [Line Items]
2021	35
2022	0
2023	0
2024	0
2025	0
Thereafter	0
Total future minimum payments	35
Transportation [Member]
Other Commitments [Line Items]
2021	119
2022	232
2023	211
2024	205
2025	191
Thereafter	2,014
Total future minimum payments	2,972
Capital Projects [Member]
Other Commitments [Line Items]
2021	297
2022	84
2023	58
2024	0
2025	0
Thereafter	0
Total future minimum payments	439
Fuel and Gas Supply [Member]
Other Commitments [Line Items]
2021	173
2022	52
2023	1
2024	0
2025	0
Thereafter	0
Total future minimum payments	226
Long-term Service Agreements [Member]
Other Commitments [Line Items]
2021	35
2022	32
2023	43
2024	26
2025	18
Thereafter	66
Total future minimum payments	220
Operating Leases [Member]
Other Commitments [Line Items]
2021	2
2022	3
2023	3
2024	3
2025	2
Thereafter	48
Total future minimum payments	61
Demand Side Management [Member]
Other Commitments [Line Items]
2021	2
2022	3
2023	0
2024	0
2025	0
Thereafter	0
Total future minimum payments	$ 5

Contractual obligation due after fourth year.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Amount of contractual obligation to be paid in fourth 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

No definition available.

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- Definition

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

No definition available.

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Amount of contractual obligation to be paid in second 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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- Definition

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).

+ References

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- Definition

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

+ References

No definition available.

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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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