Net Investment Gains (Losses) (Change in Unrealized Gains (Losses) of Available For Sales Securities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Realized and Unrealized Investment Gains Losses [Line Items]
Unrealized investment gains, before tax	$ 392,903	$ (1,248,128)	$ (254,939)
Income tax (expense) benefit	(86,350)	264,325	56,127
Noncontrolling interests	(2)	(2)	(2)
Total change in unrealized gains and losses	306,551	(983,805)	(198,814)
Debt Securities
Realized and Unrealized Investment Gains Losses [Line Items]
Unrealized investment gains, before tax	389,839	(1,216,292)	(262,221)
Fixed maturity securities with allowance for expected credit losses
Realized and Unrealized Investment Gains Losses [Line Items]
Unrealized investment gains, before tax	643	(28,370)	10,124
Investment funds
Realized and Unrealized Investment Gains Losses [Line Items]
Unrealized investment gains, before tax	3,989	(2,019)	(1,270)
Other
Realized and Unrealized Investment Gains Losses [Line Items]
Unrealized investment gains, before tax	$ (1,568)	$ (1,447)	$ (1,572)