Policyholder Contract Deposits and Other Policyholder Funds - Other policyholder funds (Details)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Insurance [Abstract]
Premium income (as a percent)	0.40%	0.40%
Policy earnings (as a percent)	1.10%	1.00%	0.90%

Percentage of participating insurance to premium income.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479756/944-50-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(14)(b)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

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