Investments (Summary Of Components Of Net Investment Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 1,207,905	$ 680,703	$ 677,347
Funds held interest income (expense)	12,324	12,754	13,271
Future policy benefit reserve income (expense)	(1,093)	(1,237)	(1,380)
Gross investment income	1,219,136	692,220	689,238
Investment expenses	(54,244)	(49,755)	(42,099)
Net investment income	1,164,892	642,465	647,139
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	561,091	542,363	520,291
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	17,276	18,776	19,505
Short Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	1,329	5,012	17,619
Limited Partnerships [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	565,265	112,853	105,815
Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross investment income before adjustments	$ 62,944	$ 1,699	$ 14,117