Business, Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Reportable Segments | Segment	3
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 6,864	$ 16,111	$ 18,115
Retained earnings (deficit)	(5,717)	(5,653)
Pre-tax adjusted earnings	(271)	(4)	(1,738)
Proceeds from Sale of Short-Term Investments	976
Payments to Acquire Short-Term Investments	$ 611
Cumulative effect of change in accounting principle, net of income tax | Minimum | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		6,000	8,000
Retained earnings (deficit)		3,000	5,000
Pre-tax adjusted earnings		1,000
Cumulative effect of change in accounting principle, net of income tax | Maximum | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		8,000	10,000
Retained earnings (deficit)		4,000	$ 6,000
Pre-tax adjusted earnings		$ 2,000