Debt instrument exit fee percentage.

No definition available.

Name:	hrmy_DebtInstrumentExitFeePercentage
Namespace Prefix:	hrmy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument repayment premium percentage.

+ References

No definition available.

+ Details

Name:	hrmy_DebtInstrumentRepaymentPremiumPercentage
Namespace Prefix:	hrmy_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=hrmy_CreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=hrmy_SeniorSecuredTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hrmy_SeniorSecuredDelayedDrawTermLoanMember
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:

Subsequent Events - Additional Information (Details) - USD ($)	Aug. 09, 2021	Aug. 21, 2020	Jan. 09, 2020
Subsequent Event [Line Items]
Proceeds from issuance of common stock, net		$ 135,435,000
Credit Agreement \| OrbiMed Royalty & Credit Opportunities, LP.
Subsequent Event [Line Items]
Aggregate principal amount			$ 200,000,000
Debt instrument exit fee percentage			7.00%
Subsequent Events \| New Credit Facility
Subsequent Event [Line Items]
Proceeds from issuance of common stock, net	$ 30,000,000
Subsequent Events \| Senior Secured Term Loan \| New Credit Facility
Subsequent Event [Line Items]
Aggregate principal amount	200,000,000
Subsequent Events \| Senior Secured Delayed Draw Term Loan \| New Credit Facility
Subsequent Event [Line Items]
Aggregate principal amount	$ 100,000,000
Subsequent Events \| Credit Agreement \| OrbiMed Royalty & Credit Opportunities, LP.
Subsequent Event [Line Items]
Debt instrument exit fee percentage	7.00%
Debt instrument repayment premium percentage	4.00%
Subsequent Events \| Common Stock \| New Credit Facility
Subsequent Event [Line Items]
Number of shares sold	1,048,951
Shares issued, price per share	$ 28.60