Income Taxes (Narrative) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Income Tax Contingency [Line Items]
Expected income refunds			$ 8
Income Taxes Receivable, Noncurrent			13
Income taxes paid	$ 9	$ 28	0	$ 8
Valuation allowance			180	$ 141
Gross tax liability for tax positions that may not be sustained under a more likely than not threshold			5
Deferred income tax payment			228
Valuation allowance, net of federal benefit			$ 180
Research Tax Credit Carryforward [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year			2041
Research and development credits			$ 10
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward			1,300
Tax effects on operating loss carryforwards			272
Internal Revenue Service (IRS) [Member] | Indefinite Tax Period [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward			956
Tax effects on operating loss carryforwards			$ 201
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year			2024
Various tax credits			$ 34
State and Local Jurisdiction [Member] | State Net Operating Loss Carryforward [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward			$ 3,450
Tax credit expiration year			2042
Minimum [Member] | Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year			2036
Maximum [Member] | Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax credit expiration year			2037