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Investments (Summary Of Net Investment Gains (Losses) And The Change In Net Unrealized Gains On Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Gain (Loss) on Securities [Line Items]
Net realized investment gains (losses)	$ (14,007)	$ 1,155	$ (18,495)	$ (2,066)
Change in fair value of securities sold during the period	(4,654)	2,434	(4,611)	13,487
Change in fair value of securities held at the end of the period	(111,356)	480,938	795,370	845,669
Total change in fair value of equity securities	(116,010)	483,372	790,759	859,156
Net investment gains (losses)	(130,017)	484,527	772,264	857,090
Change in net unrealized losses on available-for-sale investments included in other comprehensive income (loss):	(36,598)	(170,570)	(192,367)	37,799
Fixed Maturities [Member]
Gain (Loss) on Securities [Line Items]
Change in net unrealized losses on available-for-sale investments included in other comprehensive income (loss):	(36,240)	(167,992)	(184,727)	41,187
Short-term investments [Member]
Gain (Loss) on Securities [Line Items]
Change in net unrealized losses on available-for-sale investments included in other comprehensive income (loss):	$ (358)	$ (2,578)	$ (7,640)	$ (3,388)

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- Definition

The net gains or losses on investments during the period, also including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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