Goodwill and Other Intangibles - Additional Information (Details)	9 Months Ended
Sep. 30, 2021 agency reporting_unit
Business Acquisition [Line Items]
Number of reporting units \| reporting_unit	2
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Number of insurance agencies acquired \| agency	2

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration