Income Taxes (Schedule of Deductible Loss and Credit Carryforwards) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)
Deductible loss and credit carryforwards [Line Items]
Deductible amount	$ 2,636
Losses, Deferred tax asset	710
Losses, Valuation allowance	(113)
Federal
Deductible loss and credit carryforwards [Line Items]
Deductible amount	391
Losses, Deferred tax asset	$ 82
Losses, Expiration Period	2037
Federal | Federal Production and Other Credits
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deferred tax asset	$ 22
Federal | Federal Production and Other Credits | Earliest Tax Year
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2036
Federal | Federal Production and Other Credits | Latest Tax Year
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2038
State
Deductible loss and credit carryforwards [Line Items]
Deductible amount	$ 2,245
Losses, Deferred tax asset	115
Losses, Valuation allowance	(50)
State minimum tax credits	$ 378
State | Earliest Tax Year
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2025
State | Latest Tax Year
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2043
State | Investment and Other Credits
Deductible loss and credit carryforwards [Line Items]
Losses, Valuation allowance	$ (63)
Tax credits, Deferred tax asset	$ 113
State | Investment and Other Credits | Earliest Tax Year
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2025
State | Investment and Other Credits | Latest Tax Year
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2033