Segment Reporting (Schedule Of Gross Written Premium Derived From Largest Non-U.S. Market) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Canada [Member]
Segment Reporting Information [Line Items]
Gross written premiums	$ 67,765	$ 34,330

Amount of direct and assumed premiums written.

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

Name:	us-gaap_PremiumsWrittenGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration