Segment Data - Operating Results by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 29, 2018
Segment Reporting Information [Line Items]
Net sales	$ 1,009	$ 1,005	$ 1,950	$ 1,952
Adjusted EBITDA	53	62	106	110
Total assets	4,190	2,246	4,190	2,246	$ 2,233
Net income (loss) attributable to Covetrus	(10)	29	(23)	51
Plus: Depreciation and amortization	41	16	71	33
Plus: Interest expense, net	14	1	25	1
Plus: Income tax expense	5	8	1	14
Earnings before interest, taxes, depreciation, and amortization	50	54	74	99
Plus: Share-based compensation	10	2	25	4
Plus: Formation of Covetrus	6		15
Plus: Carve-out operating expenses			5
Plus: IT infrastructure	2		2
Plus: Restructuring costs	0	(6)	0	(7)
Plus: Other (income) expense items	(15)		(15)
Operating Segments | North America
Segment Reporting Information [Line Items]
Net sales	552	520	1,049	1,001
Adjusted EBITDA	43	45	78	79
Total assets	3,265	1,356	3,265	1,356
Operating Segments | Europe
Segment Reporting Information [Line Items]
Net sales	370	390	731	761
Adjusted EBITDA	19	22	35	39
Total assets	797	681	797	681
Operating Segments | APAC & Emerging Markets
Segment Reporting Information [Line Items]
Net sales	90	98	176	196
Adjusted EBITDA	4	5	8	10
Total assets	191	199	191	199
Corporate
Segment Reporting Information [Line Items]
Net sales	0	0	0	0
Adjusted EBITDA	(13)	(10)	(15)	(18)
Total assets	872	14	872	14
Eliminations
Segment Reporting Information [Line Items]
Net sales	(3)	(3)	(6)	(6)
Adjusted EBITDA	0	0	0	0
Total assets	$ (935)	$ (4)	$ (935)	$ (4)