Net Investment Gains (Losses) (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains		$ 943	$ 1,705
Fixed maturity securities, losses		(18,130)	(2,984)
Net realized gains on investment sales		1,060	905
Change in unrealized gains		43,404	93,213
Investment funds		10	(2,162)
Real estate (2)		10,739	286,192
Loans receivable		0	(32)
Other		(15,415)	(6,955)
Net realized and unrealized gains on investments in earnings before allowance for expected credit losses		22,611	369,882
Fixed maturity securities		217	(3,906)
Loans receivable		182	289
Change in allowance for expected credit losses on investments		399	(3,617)
Net investment gains		23,010	366,265
Income tax expense		(4,850)	(78,442)
After-tax net investment gains		$ 18,160	$ 287,823
Realized gain on sale of real estate investment	$ 251,000