Collateralized Reinsurance And Trust Agreements (Premiums And Losses Ceded By The Company To Affiliate) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Effects of Reinsurance [Line Items]
Ceded written premiums	$ 99,110	$ 110,188
Ceded earned premiums	78,107	90,550
Ceded losses and LAE	80,843	45,115
Assumed written premiums	2,476	2,759
Assumed earned premiums	2,476	2,759
Assumed losses and LAE

Amount of written premiums ceded to other entities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Name:	us-gaap_CededPremiumsWritten
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration