Comprehensive Income - Components of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018
Equity [Abstract]
Net income	$ (14)	[1]	$ 28
Foreign currency translation gain (loss)	1		12
Tax effect	0		0
Foreign currency translation gain (loss)	1		12
Comprehensive income	(13)		40
Comprehensive income (loss) attributable to Covetrus, Inc.	(12)		34
Comprehensive income attributable to redeemable noncontrolling interests	$ (1)		$ 6

[1] Net income earned from January 1, 2019 thru February 7, 2019 is attributed to the former parent as it was the sole shareholder prior to February 7, 2019.