Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	3 Months Ended		7 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Jul. 19, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Numerator:
Net income (loss)	$ 51	$ 859	$ (2,512)	$ 11,157	$ 11,208	$ (2,218)	$ (3,395)
Less: net income attributable to non-controlling interests		(1,085)	$ 2,512		(11,434)	$ 2,218
Net income attributable to PetIQ, Inc. — basic		$ (226)			$ (226)
Denominator:
Weighted-average shares of Class A common stock outstanding (in 000's)-- basic		13,222,583			13,222,583
Weighted Average Number of Shares Outstanding, Diluted, Total		13,222,583			13,222,583
Earnings per share of Class A common stock — basic		$ (0.02)			$ (0.02)
Earnings per share of Class A common stock — diluted		$ (0.02)			$ (0.02)