Investments - Net Investment Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Gross investment income	$ 202,524	$ 154,956	$ 160,633
Investment expenses	(6,866)	(7,047)	(6,596)
Net investment income	195,658	147,909	154,037
Fixed-maturities available for sale
Net Investment Income [Line Items]
Gross investment income	184,189	145,613	148,127
Equity securities
Net Investment Income [Line Items]
Gross investment income	11,210	8,158	6,378
Mortgage Loans
Net Investment Income [Line Items]
Gross investment income	39	0	0
Short-term investments
Net Investment Income [Line Items]
Gross investment income	5,716	817	5,774
Other
Net Investment Income [Line Items]
Gross investment income	$ 1,370	$ 368	$ 354

Amount, before investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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