Condensed Statements of Changes in Stockholders' Equity (Deficit) (Parenthetical)	3 Months Ended
Mar. 31, 2018 USD ($)
Statement Of Stockholders Equity [Abstract]
Public offering issuance costs	$ 2,600,000
At the market offering, issuance costs	$ 17,000

Issuance of common stock from at the market offering, issuance costs.

No definition available.

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