Fair Value Disclosures - Fair Value Assets Measured on Nonrecurring Basis Valuation Techniques (Details) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Assets, Fair Value Disclosure [Abstract]
Mortgage Loans held-for-investment, fair value	$ 7,107	$ 2,413
Fair Value, Measurements, Nonrecurring
Assets, Fair Value Disclosure [Abstract]
Mortgage Loans held-for-investment, fair value	1,230	1,777
Fair Value, Measurements, Nonrecurring \| Level 3
Assets, Fair Value Disclosure [Abstract]
Mortgage Loans held-for-investment, fair value	$ 989	$ 1,474
Fair Value, Measurements, Nonrecurring \| Level 3 \| Mortgage loans \| Minimum \| Median of external sources
Assets, Fair Value Disclosure [Abstract]
External Pricing Source(s)	19.7	74.1
Fair Value, Measurements, Nonrecurring \| Level 3 \| Mortgage loans \| Maximum \| Median of external sources
Assets, Fair Value Disclosure [Abstract]
External Pricing Source(s)	105.0	100.4
Fair Value, Measurements, Nonrecurring \| Level 3 \| Mortgage loans \| Weighted Average \| Median of external sources
Assets, Fair Value Disclosure [Abstract]
External Pricing Source(s)	83.5	82.3

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 10
-Topic 825
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-12

Name:	us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant