Significant Accounting Policies - Additional Information (Detail)	9 Months Ended
Sep. 30, 2023 segment
Significant of Account Policies [Line Items]
Number of reportable segments	4
Life insurance
Significant of Account Policies [Line Items]
Proportion of future policy reserves which are not universal life type	91.00%

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
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-18

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