EARNINGS PER SHARE (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Apr. 14, 2020 shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Sep. 17, 2019 $ / shares
Earnings Per Share [Abstract]
Reverse stock split conversion ratio		10
Net (loss) income attributable to Heska Corporation | $		$ (14,399)	$ (1,465)	$ 5,850
Basic weighted-average common shares outstanding (In shares)		8,653,000	7,446,000	7,220,000
Assumed exercise of dilutive stock options and restricted stock awards (in shares)		0	0	636,000
Diluted weighted-average common shares outstanding (in shares)		8,653,000	7,446,000	7,856,000
Basic earnings per share attributable to Heska Corporation (in dollars per share) | $ / shares		$ (1.66)	$ (0.20)	$ 0.81
Diluted earnings per share attributable to Heska Corporation (in dollars per share) | $ / shares		$ (1.66)	$ (0.20)	$ 0.74
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from computation of earnings per share		904,000	300,000	111,000
Series X Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion to common stock (in shares)	122,000
Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Conversion to common stock (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		458,000	0	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		118,000	0	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		328,000	300,000	111,000
Senior Convertible Note | Convertible Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt instrument, convertible, conversion price (in dollars per share) | $ / shares					$ 86.63