Debt Instrument Failure to Perform Covenant

No definition available.

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- Definition

Debt Instrument Grace Period For Defaulted Payment

+ References

No definition available.

+ Details

Name:	hnt_DebtInstrumentGracePeriodForDefaultedPayment
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum Borrowed Aggregate Principal Amount

+ References

No definition available.

+ Details

Name:	hnt_MinimumBorrowedAggregatePrincipalAmount
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of Days in Month, Per Debt Terms

+ References

No definition available.

+ Details

Name:	hnt_NumberOfDaysInMonthPerDebtTerms
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Days in Year Per Debt Terms

+ References

No definition available.

+ Details

Name:	hnt_NumberOfDaysInYearPerDebtTerms
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Months in Year Per Debt Terms

+ References

No definition available.

+ Details

Name:	hnt_NumberOfMonthsInYearPerDebtTerms
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold Amount For Noncompliance With Senior Note Indenture.

+ References

No definition available.

+ Details

Name:	hnt_ThresholdAmountForNoncomplianceWithSeniorNoteIndenture
Namespace Prefix:	hnt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of outstanding long-term debt or borrowing associated with any securities or credit agreement for which there has been a default in principal, interest, sinking fund, or redemption provisions, or any breach of covenant that existed at the end of the period and subsequently has not been cured.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(c))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph c

-Article 4

+ Details

Name:	us-gaap_DebtDefaultLongtermDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph e

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	hnt_DebtInstrumentRedemptionEventPeriodAxis=hnt_ChangeinControlandBelowInvestmentGradeRatingMember
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- Details

Name:	us-gaap_LongtermDebtTypeAxis=hnt_SixPointThreeSevenFivePercentSeniorNotesMember
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Period Type:

Financing Arrangements (Senior Notes) (Details) (USD $)	0 Months Ended	3 Months Ended
Financing Arrangements (Senior Notes) (Details) (USD $)	May 18, 2007	Mar. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Senior notes amount		$ 399,556,000us-gaap_SeniorLongTermNotes	$ 399,504,000us-gaap_SeniorLongTermNotes
6.375% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount	400,000,000
Debt instrument, stated interest rate (as a percentage)	6.375%
Debt instrument, maturity date	Jun. 01, 2017
Debt Instrument, Redemption Price (as a percentage)		100.00%
Default on senior notes		0
Number of days in year per debt terms		360 days
Number of months in year per debt terms		12 months
Number of days in month, per debt terms		30 days
Debt instrument, benchmark for variable rate basis		Treasury rate
Treasury rate basis points (as a percentage)		0.30%
Senior note, failure to perform covenant		60 days
Senior note, grace period for defaulted payment		30 days
Threshold for noncompliance		50,000,000
Accelerated principal amount threshold		$ 50,000,000
Change in Control and Below Investment Grade Rating [Member] \| 6.375% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price (as a percentage)		101.00%