Revenue Recognition (Disaggregation of Revenue by Major Product and Service Categories) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 721,789	$ 605,303	$ 1,985,717	$ 1,801,462
CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	638,017	533,130	1,756,113	1,589,397
Water segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	33,272	34,906	95,537	99,980
LPD segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	36,971	31,370	103,369	95,980
Other segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	13,529	5,897	30,698	16,105
Cag Diagnostics recurring revenue | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	567,416	460,974	1,565,595	1,382,196
IDEXX VetLab consumables | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	218,605	177,276	603,379	519,646
Rapid assay products | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	70,593	58,930	192,681	181,966
Reference laboratory diagnostic and consulting services | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	254,223	204,919	703,300	621,469
CAG Diagnostics services and accessories | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	23,995	19,849	66,235	59,115
CAG Diagnostics capital - instruments | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	29,336	32,608	72,040	92,883
Veterinary software, services and diagnostic imaging systems | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 41,265	$ 39,548	$ 118,478	$ 114,318