Other income (Details) $ in Millions	1 Months Ended
Aug. 31, 2019 USD ($)
Other income
Cash received from settlement of a working capital adjustment dispute	$ 8.9

The amount of cash received from settlement of a working capital adjustment dispute, classified as other income.

No definition available.

Name:	hdsn_CashReceivedFromSettlementOfWorkingCapitalAdjustmentDispute
Namespace Prefix:	hdsn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration