Basis of Presentation and Accounting Policies (Details) $ in Millions	3 Months Ended
Mar. 31, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Tax benefit due to the expiration of the statute of limitations with respect to a tax item impacted by the repeal of Internal Revenue Code Section 847, which related to the discounting of property-casualty loss reserves	$ 211

Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482620/740-10-25-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482620/740-10-25-10

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration