Net Investment Gains (Losses) (Net Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Investments, Debt and Equity Securities [Abstract]
Fixed maturity securities, gains	$ 5,440	$ 14,844	$ 13,680	$ 19,775
Fixed maturity securities, losses	(2,236)	(9,234)	(4,307)	(14,081)
Net realized gains on investment sales	6,256	5,727	14,828	5,727
Change in unrealized (losses) gains	(18,239)	61,914	(42,574)	(92,552)
Investment funds	(300)	913	47,371	31,096
Real estate	49,492	(7,137)	62,401	(7,824)
Loans receivable	(881)	0	(881)	0
Other	(19,071)	(5,374)	(18,299)	(23,773)
Net realized and unrealized gains (losses) on investments in earnings before allowance for expected credit losses	20,461	61,653	72,219	(81,632)
Fixed maturity securities	1,375	21,023	(16,783)	(10,727)
Loans receivable	2,228	(4,791)	3,467	(6,930)
Change in allowance for expected credit losses on investments	3,603	16,232	(13,316)	(17,657)
Net investment gains (losses)	24,064	77,885	58,903	(99,289)
Income tax (expense) benefit	(5,264)	(18,098)	(11,151)	22,476
After-tax net investment gains (losses)	$ 18,800	$ 59,787	$ 47,752	$ (76,813)