Earnings (Loss) Per Share - Reconciliation of Basic Shares to Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) attributable to Covetrus	[1]	$ 54	$ (10)	$ 20	$ (23)
Preferred Stock Dividends and Other Adjustments [Abstract]
Dividends declared on Series A Preferred Stock		(2)	0	(2)	0
Allocation of earnings to participating securities		(6)	0	(1)	0
Income (loss) available to common shareholders		$ 46	$ (10)	$ 17	$ (23)
Basic shares (in shares)		112	112	112	103
Effect of dilutive shares (in shares)		1	0	1	0
Diluted shares (in shares)		113	112	113	103
Basic (in usd per share)		$ 0.40	$ (0.09)	$ 0.15	$ (0.22)
Diluted (in usd per share)		$ 0.40	$ (0.09)	$ 0.15	$ (0.22)
Potential dilutive securities		19	5	12	3

[1] (a) Net income earned from January 1, 2019 through February 7, 2019 is attributed to the Former Parent as it was the sole shareholder prior to February 7, 2019.