XML 45 R35.htm IDEA: XBRL DOCUMENT
v3.21.2

Note 5 - Leases (Details Textual) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 USD ($) ft² | Sep. 30, 2020 USD ($) | Sep. 30, 2021 USD ($) ft² | Sep. 30, 2020 USD ($)
Operating Lease, Payments | $ | $ 327,000 | $ 342,000 | $ 1,000,000.0 | $ 1,200,000
HONG KONG |  |  |  |
Area of Land (Square Foot) | 7,300 |  | 7,300 |
Rolling Hills Estates [Member] |  |  |  |
Area of Land (Square Foot) | 4,900 |  | 4,900 |
Lessee, Operating Lease, Renewal Term (Year) | 5 years |  | 5 years |
Richmond, British Columbia [Member] |  |  |  |
Area of Land (Square Foot) | 1,600 |  | 1,600 |
Metuchen, New Jersey [Member] |  |  |  |
Area of Land (Square Foot) | 2,000 |  | 2,000 |
CHINA |  |  |  |
Lessee, Number of Branches | 8 |  | 8 |

X
- Definition Represents the lessees' number of branches. + References No definition available. + Details
Name: | nhtc_LesseeNumberOfBranches
Namespace Prefix: | nhtc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Area of land held. + References No definition available. + Details
Name: | us-gaap_AreaOfLand
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:areaItemType
Balance Type: | na
Period Type: | instant

X
- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918673-209980 + Details
Name: | us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123391704&loc=SL77918643-209977 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (g)(1) -URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980 + Details
Name: | us-gaap_OperatingLeasePayments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_StatementGeographicalAxis=country_HK
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=nhtc_RollingHillsEstatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=nhtc_RichmondBritishColumbiaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=nhtc_MetuchenNewJerseyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_CN
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |