Net Investment Gains (Losses) (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains	$ 2,943	$ 3,811	$ 16,623	$ 23,586
Fixed maturity securities, losses	(1,124)	(39,162)	(5,431)	(53,243)
Net realized gains on investment sales	2	(176)	14,830	5,551
Change in unrealized (losses) gains	(19,244)	30,693	(61,818)	(61,859)
Investment funds	2,526	203	49,897	31,299
Real estate	33,364	3,841	95,765	(3,983)
Loans receivable	0	0	(881)	0
Other	(1,280)	(6,982)	(19,578)	(30,755)
Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses	17,187	(7,772)	89,407	(89,404)
Fixed maturity securities	2,081	43,874	(14,703)	33,147
Loans receivable	233	2,876	3,700	(4,054)
Change in allowance for expected credit losses on investments	2,314	46,750	(11,003)	29,093
Net investment gains (losses)	19,501	38,978	78,404	(60,311)
Income tax expense	(4,266)	(8,855)	(15,417)	13,622
After-tax net investment gains (losses)	$ 15,235	$ 30,123	$ 62,987	$ (46,689)