EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Apr. 14, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 17, 2019
Earnings Per Share [Abstract]
Net (loss) income attributable to Heska Corporation		$ (5,219)	$ (310)	$ (16,864)	$ 263
Basic weighted-average common shares outstanding (in shares)		9,123,000	7,501,000	8,486,000	7,461,000
Assumed exercise of dilutive stock options and restricted shares		0	0	0	499,000
Diluted weighted-average common shares outstanding		9,123,000	7,501,000	8,486,000	7,960,000
Basic (loss) earnings per share attributable to Heska Corporation (in dollars per share)		$ (0.57)	$ (0.04)	$ (1.99)	$ 0.04
Diluted (loss) earnings per share attributable to Heska Corporation (in dollars per share)		$ (0.57)	$ (0.04)	$ (1.99)	$ 0.03
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share		435,000	273,000	996,000	272,000
Series X Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of convertible securities (in shares)	122,000
Traditional Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion of convertible securities (in shares)	1,508,964
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	611,000	0
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		123,000	0	56,000	0
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		312,000	273,000	329,000	272,000
Senior Convertible Note | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion price (in dollars per share)						$ 86.63