Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Unbilled Audit Premiums	$ 25	$ 10	$ (27)
Weighted average shares held in grantor trust	11,416,856
Indefinite-lived Intangible Assets [Line Items]
Basic weighted average number of shares outstanding (in shares)	276,852	277,430	280,386
Deposit contracts, liabilities	$ 33	$ 35
Depreciation	52	52	$ 53
Interest payments	138	141	155
Income taxes paid	295	244	$ 103
Other Assets
Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 102	$ 85

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Carrying amount of liabilities as of the balance sheet date pertaining to amounts received by the insurer or reinsurer from the insured (including a ceding company) under insurance or reinsurance contracts for which insurance risk is not transferred.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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Number of shares of restricted stock determined by relating the portion of time within a reporting period that restricted shares have been outstanding to the total time in that period. Restricted shares are subject to sales, contractual, regulatory or other restrictions that prevent or inhibit the holder from freely disposing of them before the restriction ends.

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Increase (Decrease) In Earned Unbilled Audit Premiums

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