Investments in Fixed Maturity Securities (AFS Allowance for Credit Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 333	$ 22,831	$ 646	$ 36,708
Change on securities for which credit losses were not previously recorded	0	1,439	10	2,001
Change on securities for which credit losses were previously recorded	(15)	(1,872)	(338)	(16,311)
Balance, end of period	318	21,837	318	21,837
Reduction due to disposals	0	(561)	0	(561)
Foreign government
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	323	20,479	216	29,603
Change on securities for which credit losses were not previously recorded	0	300	0	300
Change on securities for which credit losses were previously recorded	(5)	(1,310)	102	(10,434)
Balance, end of period	318	19,469	318	19,469
Reduction due to disposals	0	0	0	0
Mortgage-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period		562	430	158
Change on securities for which credit losses were not previously recorded		1,139	0	1,701
Change on securities for which credit losses were previously recorded		0	(430)	(158)
Balance, end of period	0	1,140	0	1,140
Reduction due to disposals		(561)	0	(561)
State and municipal
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	10	693	0	757
Change on securities for which credit losses were not previously recorded	0	0	10	0
Change on securities for which credit losses were previously recorded	(10)	(354)	(10)	(418)
Balance, end of period	0	339	0	339
Reduction due to disposals	0	0	0	0
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			0	5,026
Change on securities for which credit losses were not previously recorded				0
Change on securities for which credit losses were previously recorded				(5,026)
Balance, end of period	0	0	0	0
Reduction due to disposals				0
Asset-backed
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period		1,097	0	1,164
Change on securities for which credit losses were not previously recorded		0		0
Change on securities for which credit losses were previously recorded		(208)		(275)
Balance, end of period	$ 0	889	$ 0	889
Reduction due to disposals		$ 0		$ 0