Investments (Mortgage Loans in Nonaccrual Status by Portfolio Segment) (Details) - Mortgage Loans - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Nonaccrual [Line Items]
Financing receivable in nonaccrual status	$ 102	$ 78
Commercial
Financing Receivable, Nonaccrual [Line Items]
Financing receivable in nonaccrual status	17	11
Agricultural
Financing Receivable, Nonaccrual [Line Items]
Financing receivable in nonaccrual status	0	3
Residential
Financing Receivable, Nonaccrual [Line Items]
Financing receivable in nonaccrual status	$ 85	$ 64

Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)
-Publisher SEC

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-7

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant