Segment Reporting (Summary Of Revenue By Product And Service Category) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Revenue	$ 508,940	$ 466,569	$ 970,961	$ 884,119
Revenue, Reclassified Between Segments	400		700
CAG Diagnostics Recurring Revenue [Member]
Segment Reporting Information [Line Items]
Revenue	380,319	338,653	726,999	644,494
IDEXX Vetlab Consumables [Member]
Segment Reporting Information [Line Items]
Revenue	132,094	114,560	255,647	222,529
Rapid Assay Products [Member]
Segment Reporting Information [Line Items]
Revenue	60,266	55,777	108,161	98,863
Reference Laboratory Diagnostic And Consulting Services [Member]
Segment Reporting Information [Line Items]
Revenue	171,298	153,134	330,367	293,842
CAG Diagnostics Service And Accessories [Member]
Segment Reporting Information [Line Items]
Revenue	16,661	15,182	32,824	29,260
CAG Diagnostic Capital - Instruments [Member]
Segment Reporting Information [Line Items]
Revenue	27,716	32,165	53,899	54,808
Veterinary Software, Services and Diagnostic Imaging Systems [Member]
Segment Reporting Information [Line Items]
Revenue	31,913	29,405	62,277	58,560
CAG Segment [Member]
Segment Reporting Information [Line Items]
Revenue	439,948	400,223	843,175	757,862
Water Segment [Member]
Segment Reporting Information [Line Items]
Revenue	29,424	27,829	54,501	51,381
LPD Segment [Member]
Segment Reporting Information [Line Items]
Revenue	33,553	32,856	62,870	63,712
Other Segment [Member]
Segment Reporting Information [Line Items]
Revenue	$ 6,015	$ 5,661	$ 10,415	$ 11,164