Condensed Financial Information of Registrant (Schedule Of Condensed Financial Information Of Registrant, Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Net investment income									$ 134,858	$ 141,263	$ 135,838
Net realized investment gains (losses)									85,731	222,793	(133,520)
Other									8,287	9,044	9,275
Total revenues									3,784,511	3,972,518	3,380,004
Expenses:
Other operating expenses									285,831	269,305	244,630
Interest									17,048	17,035	17,036
Total expenses									3,326,010	3,594,449	3,410,619
Income (loss) before income taxes	$ 207,110	$ 146,631	$ 285,466	$ (180,705)	$ 28,465	$ 80,840	$ 101,595	$ 167,169	458,501	378,069	(30,615)
Income tax expense (benefit)									83,894	57,982	(24,887)
Net income (loss)	$ 166,743	$ 118,857	$ 228,211	$ (139,204)	$ 31,688	$ 69,282	$ 83,250	$ 135,867	374,607	320,087	(5,728)
Parent Company [Member]
Revenues:
Net investment income									3,323	3,735	4,661
Net realized investment gains (losses)									9,575	31,682	(10,797)
Other									0	5	2
Total revenues									12,898	35,422	(6,134)
Expenses:
Other operating expenses									3,054	2,592	2,343
Interest									17,035	17,036	17,036
Total expenses									20,089	19,628	19,379
Income (loss) before income taxes									(7,191)	15,794	(25,513)
Income tax expense (benefit)									600	2,816	(5,144)
(Loss) income before equity in net income of subsidiaries									(7,791)	12,978	(20,369)
Equity in net income of subsidiaries									382,398	307,109	14,641
Net income (loss)									$ 374,607	$ 320,087	$ (5,728)