Reinsurance (Effect Of Reinsurance On Benefit Expense) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reinsurance Disclosures [Abstract]
Direct	$ 81,254	$ 71,749	$ 72,135
Assumed	589	219	217
Ceded	(57)	(73)	(116)
Net benefit expense	$ 81,786	$ 71,895	$ 72,236

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=116637232&loc=SL114874131-224263

Reference 2: 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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- References

No definition available.

+ Details

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- Definition

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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- Definition

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

+ References

+ Details

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