ACQUISITION AND RELATED PARTY ITEMS - Additional Information (Details)			1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended
	Apr. 01, 2020 USD ($)	Dec. 05, 2019 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 36,204,000	$ 85,302,000		$ 85,302,000	$ 85,302,000
Unrecognized tax benefits, period increase (decrease)							1,000,000.0
Goodwill, period increase (decrease)							110,000
Related party loan			0	1,186,000		1,186,000	1,186,000
Operating cash outflows - operating leases							1,617,000	$ 1,344,000
Operating lease right-of-use assets			5,726,000	5,804,000		5,804,000	5,804,000
Total lease liabilities				$ 6,276,000		$ 6,276,000	$ 6,276,000
CVM Practice | Affiliated Entity
Business Acquisition [Line Items]
Number of warehouses | segment				2		2	2
Number of loans | segment				2		2	2
Operating cash outflows - operating leases							$ 23,000	0
Operating lease right-of-use assets			0	$ 169,000		$ 169,000	169,000
Total lease liabilities			0	169,000		169,000	169,000
Accounts payable, related parties			0	1,200,000		1,200,000	1,200,000
Cuattro, LLC | Heska Imaging | Affiliated Entity
Business Acquisition [Line Items]
Related party - amount of transaction							0	6,000
Heska Imaging | Affiliated Entity
Business Acquisition [Line Items]
Related party loan			0	0		0	0
Scil Animal Care Company
Business Acquisition [Line Items]
Percentage of voting interest acquired	100.00%
Cash consideration transferred	$ 111,000,000.0
Purchase price	109,753,000
Goodwill	45,799,000
Revenue of acquiree since acquisition date						37,700,000
Net income of acquiree since acquisition date						$ 200,000
Acquisition related costs				700,000			5,700,000
Revenue, net					$ 49,346,000		151,522,000	144,372,000
Net (loss) income attributable to Heska Corporation					(557,000)		(17,680,000)	(1,730,000)
Scil Animal Care Company | International
Business Acquisition [Line Items]
Goodwill	37,300,000
Scil Animal Care Company | North America
Business Acquisition [Line Items]
Goodwill	$ 8,500,000
CVM
Business Acquisition [Line Items]
Percentage of voting interest acquired		100.00%
Purchase price		$ 14,400,000
Goodwill		8,959,000
Equity interest issued and issuable		$ 9,000,000.0
Revenue of acquiree since acquisition date			800,000	2,200,000			5,200,000
Net income of acquiree since acquisition date			$ 100,000	300,000			400,000
Acquisition related costs				$ 44,000			$ 300,000
Revenue, net					32,910,000			94,462,000
Net (loss) income attributable to Heska Corporation					$ 58,000			$ 466,000