Reserve For Losses, LAE And Future Policy Benefit Reserve (Summary Of Incurred Losses With Respect To A&E Reserve On Both Gross And Net Of Reinsurance Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reserve For Losses LAE And Future Policy Benefit Reserve [Abstract]
Gross basis: Beginning of period reserves	$ 448,994	$ 441,111	$ 433,117
Gross basis: Incurred losses	(2,473)	90,009	73,336
Gross basis: Paid losses	(99,026)	(82,126)	(65,342)
Gross basis: End of period reserves	347,495	448,994	441,111
Net basis: Beginning of period reserves	318,081	319,072	319,620
Net basis: Incurred losses		37,137	53,909
Net basis: Paid losses	(56,624)	(38,128)	(54,457)
Net basis: End of period reserves	$ 261,456	$ 318,081	$ 319,072