Segment Reporting (Summary Of Revenue By Product And Service Category) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 462,021	$ 417,550
CAG Diagnostics Recurring Revenue [Member]
Segment Reporting Information [Line Items]
Revenue	346,680	305,841
IDEXX Vetlab Consumables [Member]
Segment Reporting Information [Line Items]
Revenue	123,553	107,969
IDEXX VetLab Service and Accessories [Member]
Segment Reporting Information [Line Items]
Revenue	47,895	43,086
Rapid Assay Products [Member]
Segment Reporting Information [Line Items]
Revenue	159,069	140,708
Reference Laboratory Diagnostic And Consulting Services [Member]
Segment Reporting Information [Line Items]
Revenue	16,163	14,078
CAG Diagnostic Capital - Instruments [Member]
Segment Reporting Information [Line Items]
Revenue	26,183	22,643
Veterinary Software, Services and Diagnostic Imaging Systems [Member]
Segment Reporting Information [Line Items]
Revenue	30,364	29,155
CAG Segment [Member]
Segment Reporting Information [Line Items]
Revenue	403,227	357,639
Water Segment [Member]
Segment Reporting Information [Line Items]
Revenue	25,077	23,552
LPD Segment [Member]
Segment Reporting Information [Line Items]
Revenue	29,317	30,856
Other Segment [Member]
Segment Reporting Information [Line Items]
Revenue	$ 4,400	$ 5,503