Amount held in cash and securities in trust, at least equal to the recoverable from the reinsurer

No definition available.

Name:	hum_AmountHeldInCashAndSecuritiesInTrustAtLeastEqualToRecoverableFromReinsurer
Namespace Prefix:	hum_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of reinsurers comprising other reinsurance recoverables balance

+ References

No definition available.

+ Details

Name:	hum_NumberOfReinsurersComprisingOtherReinsuranceRecoverablesBalance
Namespace Prefix:	hum_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage Of Coinsurance Agreement

+ References

No definition available.

+ Details

Name:	hum_PercentageOfCoinsuranceAgreement
Namespace Prefix:	hum_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of written premiums ceded to other entities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

+ Details

Name:	us-gaap_CededPremiumsWritten
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_EffectsOfReinsuranceLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ 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

+ Details

Name:	us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(6))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6824-158387

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21409-158489

+ Details

Name:	us-gaap_ReinsuranceRecoverables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_ProductOrServiceAxis=hum_ProtectiveLifeInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=hum_AllOthersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	hum_LongDurationInsuranceProductsAxis=hum_CoinsuranceAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_ReinsuranceRecoverableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_ReinsurerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

REINSURANCE (Details) $ in Millions	12 Months Ended
REINSURANCE (Details) $ in Millions	Dec. 31, 2021 USD ($) reinsurer	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 188	$ 194
Premiums ceded	6	29	$ 1,000
Benefits ceded	$ 2	7	$ 881
Number of reinsurers comprising other reinsurance recoverables balance \| reinsurer	10
Cash and securities in trusts held by certain reinsurers	$ 2
Protective Life Insurance Company
Effects of Reinsurance [Line Items]
Reinsurance recoverables	169
All others
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 19
100% coinsurance agreements
Effects of Reinsurance [Line Items]
Percentage of coinsurance agreement	100.00%
Reinsurance recoverables \| Reinsurer concentration risk
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 188	$ 193