Earnings (Loss) Per Share - Reconciliation of Basic Shares to Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income (loss) attributable to Covetrus	$ (54)	$ (19)	$ (980)
Adjustment for: Dividends declared on Series A preferred stock	0	(7)	0
Net income (loss) available to common shareholders	$ (54)	$ (26)	$ (980)
Denominator:
Basic, Weighted-average common shares outstanding	137	118	107
Diluted, Effect of dilutive shares (in shares)	0	0	0
Diluted shares (in shares)	137	118	107
Earnings (loss) per share:
Basic (in usd per share)	$ (0.39)	$ (0.22)	$ (9.14)
Diluted (in usd per share)	$ (0.39)	$ (0.22)	$ (9.14)
Potentially dilutive securities	5	6	6