Investments (Fixed Maturity Securities Pledged And Received As Collateral) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	$ 55,873	$ 49,548
Available-for-sale at fair value (amortized cost of $55,873 and $49,548; allowance for credit losses of $31 and $20)	60,749	56,735
Assets Held-in-trust	465	572
Estimate of Fair Value Measurement [Member]
Debt Securities, Available-for-sale [Line Items]
Assets Held-in-trust	31,173	31,179
Carrying Value [Member]
Debt Securities, Available-for-sale [Line Items]
Assets Held-in-trust	28,671	27,675
Collateral Fixed Maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available for Sale at Fair value - Amortized cost	100	148
Available-for-sale at fair value (amortized cost of $55,873 and $49,548; allowance for credit losses of $31 and $20)	103	162
Collateral Received Fixed Maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale at fair value (amortized cost of $55,873 and $49,548; allowance for credit losses of $31 and $20)	$ 1,922	$ 1,784

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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