CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Traditional Common Stock	Traditional Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance (in shares) at Dec. 31, 2018				0		7,676,000
Beginning balance at Dec. 31, 2018	$ 122,409			$ 0		$ 77		$ 257,034		$ 277		$ (134,979)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Heska Corporation	263											263
Issuance of common stock, net of shares withheld for employee taxes (in shares)						148,000
Issuance of common stock, net of shares withheld for employee taxes	(2,247)					$ 1		(2,248)
Conversion of preferred stock to common stock	29,770							29,770
Stock-based compensation	3,625							3,625
Other comprehensive income (loss)	(137)									(137)
Ending balance (in shares) at Sep. 30, 2019				0		7,824,000
Ending balance at Sep. 30, 2019	153,683			$ 0		$ 78		288,181		140		(134,716)
Beginning balance (in shares) at Jun. 30, 2019				0		7,794,000
Beginning balance at Jun. 30, 2019	122,922			$ 0		$ 78		256,952		298		(134,406)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Heska Corporation	(310)											(310)
Issuance of common stock, net of shares withheld for employee taxes (in shares)						30,000
Issuance of common stock, net of shares withheld for employee taxes	213					$ 0		213
Conversion of preferred stock to common stock	29,770							29,770
Stock-based compensation	1,246							1,246
Other comprehensive income (loss)	(158)									(158)
Ending balance (in shares) at Sep. 30, 2019				0		7,824,000
Ending balance at Sep. 30, 2019	153,683			$ 0		$ 78		288,181		140		(134,716)
Beginning balance (in shares) at Dec. 31, 2019				0	0	7,882,000	7,882,000
Beginning balance at Dec. 31, 2019	154,364	$ (18)	$ 154,346	$ 0	$ 0	$ 79	$ 79	290,216	$ 290,216	513	$ 513	(136,444)	$ (18)	$ (136,462)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Heska Corporation	(16,864)											(16,864)
Issuance of common stock, net of shares withheld for employee taxes (in shares)						64,000
Issuance of common stock, net of shares withheld for employee taxes	1,398							1,397
Issuance of preferred stock, net of issuance costs (in shares)				122,000
Issuance of preferred stock, net of issuance costs	121,786			$ 1				121,785
Conversion of preferred stock to common stock (in shares)				(122,000)		1,509,000
Conversion of preferred stock to common stock	0			$ (1)		$ 15		(14)
Stock-based compensation	6,930							6,930
Other comprehensive income (loss)	7,286									7,286
Ending balance (in shares) at Sep. 30, 2020				0		9,455,000
Ending balance at Sep. 30, 2020	274,882			$ 0		$ 95		420,314		7,799		(153,326)
Beginning balance (in shares) at Jun. 30, 2020				0		9,415,000
Beginning balance at Jun. 30, 2020	270,047			$ 0		$ 94		415,687		2,373		(148,107)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss attributable to Heska Corporation	(5,219)											(5,219)
Issuance of common stock, net of shares withheld for employee taxes (in shares)						40,000
Issuance of common stock, net of shares withheld for employee taxes	496					$ 1		495
Stock-based compensation	4,132							4,132
Other comprehensive income (loss)	5,426									5,426
Ending balance (in shares) at Sep. 30, 2020				0		9,455,000
Ending balance at Sep. 30, 2020	$ 274,882			$ 0		$ 95		$ 420,314		$ 7,799		$ (153,326)