Aggregate consideration.

No definition available.

Name:	htgm_AggregateConsideration
Namespace Prefix:	htgm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Warrant expiration date.

+ References

No definition available.

+ Details

Name:	htgm_WarrantExpirationDate
Namespace Prefix:	htgm_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ 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.(i)(2))

-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 i

-Subparagraph 2

-Article 4

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Agreed upon price for the exchange of the underlying asset.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

+ Details

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

- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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

- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

+ Details

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

- Definition

Risk-free interest rate assumption used in valuing an instrument.

+ References

+ Details

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

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of warrants not settleable in cash classified as equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=htgm_ConvertibleNoteWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=htgm_SeriesELoanWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=htgm_SeriesEStockMember
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:

Preferred Stock Warrants - Additional Information (Details) (USD $)	3 Months Ended		12 Months Ended	0 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2014	Aug. 22, 2014	Jan. 15, 2015	May 11, 2015	May 31, 2015
Class Of Warrant Or Right [Line Items]
Share price	$ 0.13us-gaap_SharePrice	$ 0.13us-gaap_SharePrice	$ 0.13us-gaap_SharePrice
Expected risk-free interest rate	1.70%	1.60%	1.20%
Expected volatility	75.00%	75.00%	70.00%
Expected term	6 years 6 months	7 years	4 years 1 month 6 days
Expected dividend yield	0.00%	0.00%
Fair value of warrants	$ 727,737	$ 741,828	$ 741,828
Fair value of Series B/C/D Stock and Series E Stock shares on grant date or measurement date	$ 0.13us-gaap_SharePrice	$ 0.13us-gaap_SharePrice	$ 0.13us-gaap_SharePrice
Subsequent Event
Class Of Warrant Or Right [Line Items]
Common stock, at the initial public offering price per shares						$ 14
Series E Stock
Class Of Warrant Or Right [Line Items]
Share price				$ 0.31
Warrants exercise price				$ 0.2189
Expected risk-free interest rate				1.60%
Expected volatility				70.00%
Expected term				4 years 6 months
Expected dividend yield				8.00%
Fair value of Series B/C/D Stock and Series E Stock shares on grant date or measurement date				$ 0.31
Series E Loan Warrants
Class Of Warrant Or Right [Line Items]
Warrants issued to acquire shares				2,512,562			23,396
Warrants exercise price				$ 0.2189			$ 23.51
Warrants expiration date	Aug. 22, 2024
Warrants exercise price				$ 0.12
Fair value of warrants	231,140	301,508	301,508	301,507
Convertible Note Warrants
Class Of Warrant Or Right [Line Items]
Warrants issued to acquire shares					9,311,586
Warrants exercise price					$ 0.2189
Warrants expiration date	Jan. 14, 2022
Aggregate consideration					$ 1,354