XML 73 R57.htm IDEA: XBRL DOCUMENT
v3.19.1

Related Party Transactions - Summary of Participation (Details) - Private Placement $ in Thousands | 1 Months Ended
--- | ---
Dec. 31, 2017 USD ($) shares
Related Party Transaction [Line Items] |
Units Purchased | shares | 372,956
Subscription Amount | $ | $ 3,655
A&B (HK) Company Ltd. |
Related Party Transaction [Line Items] |
Units Purchased | shares | 204,081
Subscription Amount | $ | $ 2,000
Director 1 |
Related Party Transaction [Line Items] |
Units Purchased | shares | 76,530
Subscription Amount | $ | $ 750
Director 2 |
Related Party Transaction [Line Items] |
Units Purchased | shares | 51,019
Subscription Amount | $ | $ 500
CEO |
Related Party Transaction [Line Items] |
Units Purchased | shares | 25,510
Subscription Amount | $ | $ 250
CFO/CEO |
Related Party Transaction [Line Items] |
Units Purchased | shares | 15,816
Subscription Amount | $ | $ 155

X
- Definition The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity. + 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=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOrSaleOfEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=hsdt_AAndBCompanyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=hsdt_DirectorOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=hsdt_DirectorTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_ChiefExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=hsdt_ChiefFinancialOfficerOrChiefOperatingOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |