Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018
Equity [Abstract]
Net income (loss)	$ (10)	[1]	$ 31	$ (23)	[1]	$ 59
Foreign currency translation gain (loss), net of tax				4		(26)
Pension adjustment gain, net of tax				1		0
Comprehensive income (loss)				(18)		33
Comprehensive income (loss) attributable to Covetrus, Inc.	(6)		(7)	(19)		27
Comprehensive loss attributable to redeemable non-controlling interests	0		0	1		6
Comprehensive income (loss)	$ (6)		$ (7)	$ (18)		$ 33

[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 (b) See discussion in Note 3 - Business Acquisitions