Revenue Recognition (Disaggregation of Revenue by Major Product and Service Categories) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 637,592	$ 620,103	$ 1,263,928	$ 1,196,159
CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	566,100	547,349	1,118,096	1,056,267
Water segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	28,116	34,764	62,265	65,074
LPD segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	32,244	33,104	66,398	64,610
Other segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	11,132	4,886	17,169	10,208
Cag Diagnostics recurring revenue | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	510,254	477,431	998,179	921,222
IDEXX VetLab consumables | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	196,061	175,159	384,774	342,370
Rapid assay products | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	64,658	68,605	122,088	123,036
Reference laboratory diagnostic and consulting services | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	228,816	213,892	449,077	416,550
CAG Diagnostics services and accessories | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	20,719	19,775	42,240	39,266
CAG Diagnostics capital - instruments | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	18,871	31,526	42,704	60,275
Veterinary software, services and diagnostic imaging systems | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 36,975	$ 38,392	$ 77,213	$ 74,770