Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	1-13412
Entity Registrant Name	HUDSON TECHNOLOGIES INC /NY
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-3641539
Entity Address, Address Line One	1 Blue Hill Plaza
Entity Address, Address Line Two	P.O. Box 1541
Entity Address, City or Town	Pearl River
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10965
City Area Code	845
Local Phone Number	735-6000
Title of 12(b) Security	Common stock, $0.01 par value
Security Exchange Name	NASDAQ
Trading Symbol	HDSN
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		43,969,748
Entity Central Index Key	0000925528
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Amendment Flag	false