Nuclear Decommissioning Trust Funds - Summary of Available-for-Sale Debt Securities with Unrealized Losses (Details) $ in Millions	Jun. 30, 2024 USD ($)
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	$ 325
Unrealized Losses	(5)
Fair Value, One Year or Longer	154
Unrealized Losses, One Year or Longer	(3)
Corporate debt securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	78
Unrealized Losses	(1)
Fair Value, One Year or Longer	23
Municipal debt securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	64
Unrealized Losses	(1)
Fair Value, One Year or Longer	49
Unrealized Losses, One Year or Longer	(1)
U.S. Government debt securities
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Fair Value	183
Unrealized Losses	(3)
Fair Value, One Year or Longer	105
Unrealized Losses, One Year or Longer	$ (2)

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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