Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Net Investment Income [Line Items]
Gross investment income	$ 175,485	$ 160,027
Investment expense	(1,973)	(1,450)
Net investment income	173,512	158,577
Fixed maturity securities, including cash and cash equivalents and loans receivable
Net Investment Income [Line Items]
Gross investment income	101,284	94,677
Investment funds
Net Investment Income [Line Items]
Investment funds	52,012	38,935
Arbitrage trading account
Net Investment Income [Line Items]
Gross investment income	9,187	19,074
Equity securities
Net Investment Income [Line Items]
Gross investment income	2,146	1,161
Real estate
Net Investment Income [Line Items]
Gross investment income	$ 10,856	$ 6,180

Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.

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Amount of expenses related to the generation of investment income.

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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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Amount, after 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.

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