Investments (Composition Of Current And Past Due Mortgage Loans On Real Estate) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Mortgage Loans On Real Estate Aging [Abstract]
Current	$ 16,875	$ 16,279
Allowance for credit losses	(161)	(2)
Unamortized premium (discount)	8	6
Mark-to-market gains (losses)	26
Total carrying value	16,791	16,339
30 to 59 Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	16	30
60 to 89 Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	4	10
90 Or More Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	23	16
Commercial [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Current	16,168	15,620
Allowance for credit losses	(126)
Unamortized premium (discount)	(16)	(17)
Mark-to-market gains (losses)	26
Total carrying value	16,052	15,606
Commercial [Member] \| 30 to 59 Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due		3
Residential [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Current	707	659
Allowance for credit losses	(35)	(2)
Unamortized premium (discount)	24	23
Total carrying value	739	733
Residential [Member] \| 30 to 59 Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	16	27
Residential [Member] \| 60 to 89 Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	4	10
Residential [Member] \| 90 Or More Days Past Due [Member]
Mortgage Loans On Real Estate Aging [Abstract]
Past due	$ 23	$ 16

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- Definition

The amount of premium (net of discount) that was originally recognized at the issuance of the mortgage loan that has yet to be amortized.

+ References

No definition available.

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- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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- Definition

Amount of financing receivable not past due.

+ References

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Amount of financing receivable past due.

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- Definition

Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

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