XML 26 R15.htm IDEA: XBRL DOCUMENT
v3.25.3

Accrued expenses and other current liabilities | 9 Months Ended
--- | ---
Sep. 30, 2025
Accrued expenses and other current liabilities |
Accrued expenses and other current liabilities | Note 9 – Accrued expenses and other current liabilities Elements of Accrued expenses and other current liabilities are as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | September 30, |  | December 31,
​ | ​ | 2025 | ​ | 2024
​ | ​ | (unaudited) | ​ | ​ | ​
(in thousands) | ​ |  | ​ | ​ |  | ​
Accrued expenses | ​ | $ | 17,246 | ​ | $ | 12,320
Cylinder deposits | ​ |  | 22,783 | ​ |  | 19,426
Lease obligations | ​ |  | 2,049 | ​ |  | 1,961
Other current liabilities | ​ |  | 124 | ​ |  | 106
Total | ​ | $ | 42,202 | ​ | $ | 33,813
​

X
- Definition NA + References No definition available. + Details
Name: | hdsn_AccruedExpensesAndOtherCurrentLiabilitiesAbstract
Namespace Prefix: | hdsn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for accounts payable, accrued expenses, and other liabilities that are classified as current at the end of the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 720 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483384/720-30-45-1 + Details
Name: | us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration