Revenue Recognition (Disaggregation of Revenue by Major Product and Service Categories) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 810,421	$ 721,789	$ 2,414,270	$ 1,985,717
CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	732,495	638,017	2,170,857	1,756,113
Water segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	38,143	33,272	109,374	95,537
LPD segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	29,126	36,971	101,920	103,369
Other segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,657	13,529	32,119	30,698
Cag Diagnostics recurring revenue | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	638,358	567,416	1,916,938	1,565,595
IDEXX VetLab consumables | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	252,714	218,605	755,158	603,379
Rapid assay products | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	76,974	70,593	230,472	192,681
Reference laboratory diagnostic and consulting services | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	282,301	254,223	851,757	703,300
CAG Diagnostics services and accessories | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	26,369	23,995	79,551	66,235
CAG Diagnostics capital - instruments | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	39,401	29,336	105,645	72,040
Veterinary software, services and diagnostic imaging systems | CAG segment revenue
Disaggregation of Revenue [Line Items]
Total revenue	$ 54,736	$ 41,265	$ 148,274	$ 118,478