Insurance and Contractholder Liabilities - Narrative (Details) - USD ($) $ in Billions	Dec. 31, 2020	Dec. 31, 2019
Insurance and Contractholder Liabilities [Line Items]
Percent of the liability for future policy benefits supported by assets held in trust	20.00%
Minimum
Insurance and Contractholder Liabilities [Line Items]
Liability for future policy benefits interest rate	1.00%
Maximum
Insurance and Contractholder Liabilities [Line Items]
Liability for future policy benefits interest rate	9.00%
U.S. Medical
Insurance and Contractholder Liabilities [Line Items]
Total of incurred but not reported liabilities plus expected claim development on reported claims, including reported claims in process	$ 2.9	$ 2.7
Percent of health claims paid within one year	95.00%

No definition available.

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- Definition

Represents the total liability for incurred but not reported claims plus expected claim development on reported claims, including reported claims in process. Excludes amounts due for physician incentives and other medical care expenses and services payable.

+ References

No definition available.

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- Definition

Liability For Future Policy Benefits, Percent Supported By Assets Held In Trust

+ References

No definition available.

+ Details

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- Definition

Rate of interest used to calculate the liability for future policy benefits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121643868&loc=d3e14931-158439

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- Definition

Percentage of average annual payout, after reinsurance, in the first year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 4G
-URI http://asc.fasb.org/extlink&oid=116884468&loc=SL65671329-158438

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