Business Acquisitions - Pro Forma Information (Details) - VFC - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Acquisition [Line Items]
Net Sales	$ 965	$ 992
Net income (loss)	(24)	(13)
Net income (loss) attributable to Covetrus	$ (23)	$ (13)
Net income per common share: basic (in usd per share)	$ (0.25)	$ (0.19)
Net income per common share: diluted (in usd per share)	$ (0.25)	$ (0.19)