Percentage amount the holder would beneficially own of the company's outstanding common stock.

No definition available.

Name:	hrtx_BeneficialOwnershipAfterConversion
Namespace Prefix:	hrtx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Common shares registered for resale in connection with convertible notes.

+ References

No definition available.

+ Details

Name:	hrtx_CommonSharesRegisteredForResaleInConnectionWithConvertibleNotes
Namespace Prefix:	hrtx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Convertible debt issuable in connection with private placement.

+ References

No definition available.

+ Details

Name:	hrtx_ConvertibleDebtIssuableInConnectionWithPrivatePlacement1
Namespace Prefix:	hrtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the holder.

+ References

No definition available.

+ Details

Name:	hrtx_ConvertibleNotesPayableRelatedPartiesCurrent
Namespace Prefix:	hrtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under a debt agreement on the amount that could be borrowed with a combination of, but not limited to, a line of credit and term loan.

+ References

No definition available.

+ Details

Name:	hrtx_DebtAgreementMaximumBorrowingCapacity
Namespace Prefix:	hrtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The multiple of principal used in calculating the number of shares converted from the notes.

+ References

No definition available.

+ Details

Name:	hrtx_DebtInstrumentConversionRatioMultipleOfPrincipal
Namespace Prefix:	hrtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares per $1,000 of principal of note.

+ References

No definition available.

+ Details

Name:	hrtx_DebtInstrumentConversionRatioShares
Namespace Prefix:	hrtx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of shares of equity instruments that the holder of the debt instrument would receive if the debt was converted to equity.

+ References

No definition available.

+ Details

Name:	hrtx_DebtInstrumentConvertibleNumberSharesOfEquityInsturments
Namespace Prefix:	hrtx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants that accompanies borrowing money under the debt instrument.

+ References

No definition available.

+ Details

Name:	hrtx_DebtInstrumentNumberOfWarrants
Namespace Prefix:	hrtx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Notice period associated with beneficial ownership percentage limitation, convertible notes.

+ References

No definition available.

+ Details

Name:	hrtx_NoticePeriodAssociatedWithBeneficialOwnershipPercentageLimitationConvertibleNotes
Namespace Prefix:	hrtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from a debt that is subject to the achievement of a corporate milestone.

+ References

No definition available.

+ Details

Name:	hrtx_ProceedsFromIssuanceOfLongtermDebtSubjectToAchievementOfCorporateMilestone
Namespace Prefix:	hrtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Definition

Amount of a favorable spread to a debt holder between the amount of debt being converted and the value of the securities received upon conversion. This is an embedded conversion feature of convertible debt issued that is in-the-money at the commitment date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21538-112644

+ Details

Name:	us-gaap_DebtInstrumentConvertibleBeneficialConversionFeature
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: 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=64930785&loc=d3e28551-108399

+ Details

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

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

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

+ Details

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

- Definition

Amount of increase (decrease) in debt instruments, classified as other.

+ References

+ Details

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

- Definition

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

+ 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

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=64930739&loc=d3e28878-108400

+ Details

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

- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.9)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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

- Definition

Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph 8
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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

- Definition

The amount for notes payable (written promise to pay), payable to related parties, which are due after one year (or one business cycle).

+ 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.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.23)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Interest paid other than in cash for example by issuing additional debt securities. As a noncash item, it is added to net income when calculating cash provided by or used in operations using the indirect method.

+ References

+ Details

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

- Definition

The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

+ Details

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

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_ConvertibleDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=hrtx_InCaseOfDebtConversionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hrtx_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=hrtx_TangCapitalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 6 - Secured Notes to Related Party (Details Textual) - USD ($)				1 Months Ended	3 Months Ended
	Aug. 05, 2016	Aug. 02, 2016	Jul. 29, 2011	Apr. 30, 2011	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Convertible Debt Issuable in Connection with Private Placement				$ 4,500,000
Proceeds from Convertible Debt				$ 4,300,000
Common Shares Registered for Resale in Connection with Convertible Notes			3,500,000
Interest Expense, Debt, Excluding Amortization					$ 100,000	$ 100,000
Amortization of Debt Discount (Premium)					185,000	166,000
Convertible Notes Payable, Related Parties, Current					3,096,000		$ 2,911,000
Interest Expense					1,030,000	133,000
Notes Payable, Related Parties, Noncurrent					50,000,000		$ 50,000,000
Convertible Debt [Member]
Debt Instrument, Interest Rate, Stated Percentage				6.00%
Debt Instrument Conversion Ratio Multiple of Principal				$ 1,000
Beneficial Ownership after Conversion				9.99%
Notice Period Associated with Beneficial Ownership Percentage Limitation Convertible Notes				61 days
Paid-in-Kind Interest					100,000
Debt Instrument, Increase (Decrease), Other, Net					100,000
Debt Instrument, Face Amount					6,100,000
Debt Instrument, Unamortized Discount					$ 3,000,000
Debt Instrument, Convertible, Number Shares of Equity Insturments					7,600,000
Debt Instrument, Term				10 years
Convertible Debt [Member] \| In Case of Debt Conversion [Member]
Debt Instrument, Face Amount					$ 6,100,000
Convertible Debt [Member] \| Common Stock [Member]
Debt Instrument Conversion Ratio Shares				1,250
Term Loan [Member] \| Tang Capital [Member]
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Debt Agreement, Maximum Borrowing Capacity		$ 100,000,000
Debt Instrument, Term		2 years
Proceeds from Issuance of Long-term Debt	$ 50,000,000
Proceeds from Issuance of Long-term Debt, Subject to Achievement of Corporate Milestone		$ 50,000,000
Interest Expense					1,000,000	$ 0
Notes Payable, Related Parties, Noncurrent					$ 50,000,000
Debt Instrument, Fee Amount	$ 0
Debt Instrument, Number of Warrants	0
Debt Instrument, Convertible, Beneficial Conversion Feature	$ 0