Markel Fronting Arrangement - Narrative (Details) - Hagerty Reinsurance Limited $ in Millions	12 Months Ended
Dec. 31, 2025 USD ($)
Markel Fronting Arrangment [Line Items]
Premium percentage	100.00%
Ownership interest	100.00%
Fronting fee percentage	2.00%
Consideration received, deposit liability	$ 50.5
Estimated value liability assumed	42.7
Deposit liability, deferred gain	$ 7.8

Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482987/272-10-50-3

Name:	us-gaap_LimitedLiabilityCompanyLLCOrLimitedPartnershipLPMembersOrLimitedPartnersOwnershipInterest
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration