Nature of Operations and Basis of Presentation - Segment Information (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($) segment state
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of states in which we are licensed as insurer \| state	50
Number of reportable segments \| segment	1
Cash on deposit with Lloyd's of London \| $	$ 21,331

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration