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Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net Investment Income [Line Items]
Gross investment income	$ 322,083	$ 226,113
Investment expense	(2,244)	(2,715)
Net investment income	319,839	223,398
Fixed maturity securities, including cash and cash equivalents and loans receivable
Net Investment Income [Line Items]
Gross investment income	335,248	195,642
Arbitrage trading account (1)
Net Investment Income [Line Items]
Gross investment income	(29,349)	2,180
Equity securities
Net Investment Income [Line Items]
Gross investment income	11,336	13,746
Investment funds
Net Investment Income [Line Items]
Gross investment income	18,011	18,256
Real estate
Net Investment Income [Line Items]
Gross investment income	$ (13,163)	$ (3,711)

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