Net Investment (Losses) Gains (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Jun. 30, 2023	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains			$ 299	$ 1,053	$ 1,357	$ 3,405
Fixed maturity securities, losses			(2,700)	(2,309)	(24,470)	(8,752)
Net realized gains on investment sales (2)			23,631	0	135,763	946
Change in unrealized (losses) gains			(19,059)	(50,384)	45,605	(88,701)
Investment funds			(3,329)	(1,717)	(3,417)	(6,241)
Real estate (3) (4)			(24,234)	9,026	(68,944)	295,576
Loans receivable			(1,428)	0	(1,428)	(32)
Other			(14,035)	(21,951)	(34,063)	(56,537)
Net realized and unrealized (losses) gains on investments in earnings before allowance for expected credit losses			(40,855)	(66,282)	50,403	139,664
Fixed maturity securities			(2,112)	(1,311)	(8,946)	(12,091)
Loans receivable			541	183	(2,218)	(274)
Change in allowance for expected credit losses on investments			(1,571)	(1,128)	(11,164)	(12,365)
Net investment (losses) gains			(42,426)	(67,410)	39,239	127,299
Income tax benefit (expense)			9,405	14,456	(8,033)	(26,466)
After-tax net investment (losses) gains			(33,021)	$ (52,954)	31,206	$ 100,833
Realized gain on sale of real estate investment		$ 251,000
Gain on sale of investment	$ 88,000
Real estate impairment			$ 21,000		$ 72,000