Loss And Loss Adjustment Expense Reserves (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended			7 Months Ended
	Jan. 31, 2018	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018	Jul. 31, 2018
Unusual or Infrequent Item, or Both [Line Items]
Prior year claims and claims adjustment expense			$ 27,468	$ 10,758
Adjustments for prior year claims			612,773	557,457
Loss from catastrophes			14,000	14,000
Credit Agreement [Member] | LIBOR [Member] | FFL [Member]
Unusual or Infrequent Item, or Both [Line Items]
Basis spread on variable rate	1.28%				1.05%	1.20%
Catastrophe [Member]
Unusual or Infrequent Item, or Both [Line Items]
Adjustments for prior year claims			4,000	3,000
Liability for catastrophe claims, carrying amount			$ 18,000
Loss from catastrophes				$ 17,000
Fire [Member]
Unusual or Infrequent Item, or Both [Line Items]
Loss from catastrophes, net of reinsurance benefits		$ 40,000
Liability for catastrophe claims, carrying amount		208,000
Benefit from sale of subrogation rights		$ 10,000