Lending Activities - Rollforward of the changes in the allowance for credit losses on mortgage and other loans receivable (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, beginning of period	$ 783	$ 719	$ 727	$ 771
Loans charged off	(1)	(14)	(12)	(77)
Net charge-offs	(1)	(14)	(12)	(77)
Addition to (release of) allowance for loan losses	34	13	101	24
Allowance, end of period	816	718	816	718
Off-balance-sheet commitments	8		8		$ 7
Commercial Mortgages
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, beginning of period	629	586	594	626
Loans charged off	0	(14)	(8)	(76)
Net charge-offs	0	(14)	(8)	(76)
Addition to (release of) allowance for loan losses	9	(11)	52	11
Allowance, end of period	638	561	638	561
Off-balance-sheet commitments	8	17	8	17
Other Loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance, beginning of period	154	133	133	145
Loans charged off	(1)	0	(4)	(1)
Net charge-offs	(1)	0	(4)	(1)
Addition to (release of) allowance for loan losses	25	24	49	13
Allowance, end of period	$ 178	$ 157	$ 178	$ 157

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
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-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.9-03(7)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Amount, excluding accrued interest, of decrease (increase) in allowance for credit loss on financing receivable from writeoff (recovery). Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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