Investments (Realized Investment Gains Losses, Net) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024		Sep. 30, 2025	Sep. 30, 2024
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ (347,869)	$ (651,518)	[1]	$ (1,273,607)	$ 150,425	[1]
Fixed maturities
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(29,083)	(37,870)		(45,205)	(53,338)
Commercial mortgage and other loans
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(12,795)	(3,533)		(19,220)	(8,152)
LPs/LLCs
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	0	1		(6)	(35)
Derivatives
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(258,934)	(573,164)		(1,083,536)	215,801
Short-term investments and cash equivalents
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	138	(11)		171	(91)
Ceded income on modified coinsurance investments
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	(47,014)	(36,929)		(125,816)	(3,912)
Other
Schedule Of Gain Loss On Investments [Line Items]
Realized Investment gains (losses), net	$ (181)	$ (12)		$ 5	$ 152

[1] Amounts reflect revision to prior period Financial Statements. See Note 17 for additional information.