EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net (loss) income attributable to Heska Corporation	$ (1,898)	$ (5,219)	$ (594)	$ (16,864)
Basic weighted-average common shares outstanding (in shares)	10,195	9,123	9,949	8,486
Dilutive effect of stock options and restricted stock awards	0	0	0	0
Diluted weighted-average common shares outstanding	10,195	9,123	9,949	8,486
Basic (loss) earnings per share attributable to Heska Corporation (in dollars per share)	$ (0.19)	$ (0.57)	$ (0.06)	$ (1.99)
Diluted (loss) earnings per share attributable to Heska Corporation (in dollars per share)	$ (0.19)	$ (0.57)	$ (0.06)	$ (1.99)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share	1,400	435	1,377	996
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share	0	0	0	611
Senior Convertible Note
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share	996	123	996	56
Stock Options And Restricted Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share	404	312	381	329