Business, Basis of Presentation and Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	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]
Stockholder's Equity, Including Portion Attributable to Noncontrolling Interest	$ (5,369)	$ (6,009)	$ (6,514)	$ (5,596)	$ (7,985)	$ (8,536)
Retained Earnings (Deficit)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholder's Equity, Including Portion Attributable to Noncontrolling Interest							$ 5,200
AOCI Attributable to Parent
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholder's Equity, Including Portion Attributable to Noncontrolling Interest							$ 3,900