Fair Value Measures and Disclosures (Policies)	9 Months Ended
Sep. 30, 2025
Fair Value Disclosures [Abstract]
Fair Value Measurements	For a description of the policies, methods and assumptions that are used to estimate fair value and determine the fair value hierarchy for each class of financial instruments, see Note 12 in the Company's 2024 Form 10-K. Level 3 Financial Assets and Financial Liabilities Certain inputs for instruments classified in Level 3 are unobservable (supported by little or no market activity) and significant to their resulting fair value measurement. Unobservable inputs reflect the Company's best estimate of what hypothetical market participants would use to determine a transaction price for the asset or liability at the reporting date. Additionally, as discussed in Note 9E in the Company's 2024 Form 10-K, the Company classifies variable annuity assets and liabilities in Level 3 of the fair value hierarchy. Information about Debt Securities The significant unobservable input used to value our corporate and government debt securities and mortgage and other asset-backed securities is an adjustment for liquidity. This adjustment is needed to reflect current market conditions and issuer circumstances when there is limited trading activity for the security. Total gains and losses included in Shareholders' net income in the tables above are reflected in the Consolidated Statements of Income as Net investment gains (losses) and Net investment income. Gains and losses included in Other comprehensive income (loss), net of tax, in the tables above are reflected in Net unrealized (depreciation) appreciation on securities and derivatives in the Consolidated Statements of Comprehensive Income. Transfers into or out of the Level 3 category occur when unobservable inputs, such as the Company's best estimate of what a market participant would use to determine a current transaction price, become more or less significant to the fair value measurement. Market activity typically decreases during periods of economic uncertainty, and this decrease in activity reduces the availability of market observable data. As a result, the level of unobservable judgment that must be applied to the pricing of certain instruments increases and is typically observed through the widening of liquidity spreads.Assets and Liabilities Measured at Fair Value under Certain Conditions Some financial assets and liabilities are not carried at fair value, such as commercial mortgage loans that are carried at unpaid principal, investment real estate that is carried at depreciated cost and equity securities with no readily determinable fair value when there are no observable market transactions. However, these financial assets and liabilities may be measured using fair value under certain conditions, such as when investments become impaired and are written down to their fair value, or when there are observable price changes from orderly market transactions of equity securities that otherwise had no readily determinable fair value.
Separate Accounts	Separate Accounts The investment income and fair value gains and losses of Separate account assets generally accrue directly to the contractholders and, together with their deposits and withdrawals, are excluded from the Company's Consolidated Statements of Income and Cash Flows.Separate account assets classified in Level 3 primarily support the Company's pension plans and include certain newly issued, privately placed, complex or illiquid securities that are priced using methods discussed above, as well as commercial mortgage loans.

Fair Value Measures and Disclosures (Policies)

9 Months Ended

Sep. 30, 2025

For a description of the policies, methods and assumptions that are used to estimate fair value and determine the fair value hierarchy for each class of financial instruments, see Note 12 in the Company's 2024 Form 10-K.

Level 3 Financial Assets and Financial Liabilities

Certain inputs for instruments classified in Level 3 are unobservable (supported by little or no market activity) and significant to their resulting fair value measurement. Unobservable inputs reflect the Company's best estimate of what hypothetical market participants would use to determine a transaction price for the asset or liability at the reporting date. Additionally, as discussed in Note 9E in the Company's 2024 Form 10-K, the Company classifies variable annuity assets and liabilities in Level 3 of the fair value hierarchy.

Information about Debt Securities

The significant unobservable input used to value our corporate and government debt securities and mortgage and other asset-backed securities is an adjustment for liquidity. This adjustment is needed to reflect current market conditions and issuer circumstances when there is limited trading activity for the security.

Total gains and losses included in Shareholders' net income in the tables above are reflected in the Consolidated Statements of Income as Net investment gains (losses) and Net investment income. Gains and losses included in Other comprehensive income (loss), net of tax, in the tables above are reflected in Net unrealized (depreciation) appreciation on securities and derivatives in the Consolidated Statements of Comprehensive Income.

Transfers into or out of the Level 3 category occur when unobservable inputs, such as the Company's best estimate of what a market participant would use to determine a current transaction price, become more or less significant to the fair value measurement. Market activity typically decreases during periods of economic uncertainty, and this decrease in activity reduces the availability of market observable data. As a result, the level of unobservable judgment that must be applied to the pricing of certain instruments increases and is typically observed through the widening of liquidity spreads.Assets and Liabilities Measured at Fair Value under Certain Conditions

Some financial assets and liabilities are not carried at fair value, such as commercial mortgage loans that are carried at unpaid principal, investment real estate that is carried at depreciated cost and equity securities with no readily determinable fair value when there are no observable market transactions. However, these financial assets and liabilities may be measured using fair value under certain conditions, such as when investments become impaired and are written down to their fair value, or when there are observable price changes from orderly market transactions of equity securities that otherwise had no readily determinable fair value.

Separate Accounts

The investment income and fair value gains and losses of Separate account assets generally accrue directly to the contractholders and, together with their deposits and withdrawals, are excluded from the Company's Consolidated Statements of Income and Cash Flows.Separate account assets classified in Level 3 primarily support the Company's pension plans and include certain newly issued, privately placed, complex or illiquid securities that are priced using methods discussed above, as well as commercial mortgage loans.