Reinsurance (Effect Of Reinsurance On Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reinsurance Disclosures [Abstract]
Direct	$ 85,168	$ 79,110	$ 70,789
Assumed	2,967	2,733	1,179
Ceded	(90)	(57)	(73)
Net benefit expense	$ 88,045	$ 81,786	$ 71,895

Amount, before effect of policies assumed or ceded, of expense related to provision for policy benefits and costs incurred.

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- Definition

Amount, after effects of policies assumed or ceded, of expense related to the provision for policy benefits and costs incurred.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.5)
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
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No definition available.

+ Details

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Amount of policy benefits and costs incurred for policies assumed.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6811-158387

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Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

+ References

+ Details

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