ACQUISITION AND RELATED PARTY ITEMS - Additional Information (Details) $ / shares in Units, $ in Thousands							1 Months Ended	6 Months Ended	12 Months Ended
	Oct. 05, 2020 USD ($)	Apr. 01, 2020 USD ($)	Mar. 30, 2020 USD ($)	Dec. 05, 2019 USD ($)	Feb. 22, 2019 USD ($)	Dec. 21, 2018 USD ($) $ / shares shares	Dec. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill							$ 36,204		$ 88,276	$ 36,204	$ 26,679
Acquired additions based on prior year tax positions									1,072	0
Unrecognized tax benefits							0		808	0	0
Cash paid for amounts included in the measurement of lease liabilities:									2,213	1,800
Operating lease right-of-use assets							5,726		5,457	5,726
Operating lease liability									5,945
Common stock, par value (in dollars per share) | $ / shares						$ 0.01
Repayments of related party debt									$ 1,140	0	0
Cuattro, LLC
Business Acquisition [Line Items]
Consideration transferred shares issued | shares						54,763
Shares issued as consideration, value						$ 5,400
Payments for asset acquisition						2,800
Asset acquisition, consideration transferred						$ 8,200
Acquired finite-lived intangible assets, weighted average useful life						10 years
CVM Practice | Affiliated Entity
Business Acquisition [Line Items]
Number of warehouses | segment									2
Cash paid for amounts included in the measurement of lease liabilities:									$ 31	0
Operating lease right-of-use assets							0		200	0
Operating lease liability							0		200	0
Repayments of related party debt									1,100
Cuattro, LLC | Heska Imaging
Business Acquisition [Line Items]
Related party - amount of transaction									0	6	4,600
Scil Animal Care Company
Business Acquisition [Line Items]
Percentage of voting interest acquired		100.00%
Payments to acquire business		$ 110,300	$ 111,000
Purchase price		110,290
Goodwill		46,000
Goodwill, period increase (decrease)									200
Acquired additions based on prior year tax positions									1,100
Unrecognized tax benefits									800
Revenue of acquiree since acquisition date								$ 61,300
Earnings or loss of acquiree since acquisition date								$ 1,100
Acquisition related costs									6,300	700
Revenue, net									215,874	201,700
Net (loss) income attributable to Heska Corporation									(15,215)	(2,487)
Scil Animal Care Company | International Segment
Business Acquisition [Line Items]
Goodwill		37,300
Scil Animal Care Company | North America Segment
Business Acquisition [Line Items]
Goodwill		$ 8,700
CVM
Business Acquisition [Line Items]
Percentage of voting interest acquired				100.00%
Purchase price				$ 14,400
Goodwill				$ 8,959
Goodwill, period increase (decrease)									110
Revenue of acquiree since acquisition date							800
Earnings or loss of acquiree since acquisition date							$ 100
Acquisition related costs									$ 600	100
Revenue, net										130,434	135,344
Net (loss) income attributable to Heska Corporation										$ (788)	$ 5,970
Optomed
Business Acquisition [Line Items]
Percentage of voting interest acquired	30.00%				70.00%
Payments to acquire business	$ 500				$ 200
Debt assumed in acquisition					$ 400