Additional Insurance Liabilities - Schedule of Additional Liability Long Duration Insurance Revenue and Interest Accretion (Expense) Recognized (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Insurance [Abstract]
Gross assessments	$ 125	$ 131	$ 252	$ 263	$ 513
Interest accretion	$ 27	$ 25	$ 53	$ 50	$ 102

Amount of interest income (expense) for present value of total expected payment to policyholder in excess of present value of total expected assessment. Excludes benefit classified as market risk benefit or under provisions of Topic 815 on derivative and hedging.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 13I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-13I

Name:	us-gaap_AdditionalLiabilityLongDurationInsuranceInterestIncomeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration