Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 605,303			$ 545,448			$ 1,801,462	$ 1,663,856
Income (loss) from operations	139,802			117,350			437,215	375,988
Interest expense, net	(7,004)			(8,311)			(23,503)	(25,291)
Income before provision for income taxes	132,798			109,039			413,712	350,697
Provision for income taxes	23,960			15,825			76,464	59,327
Net income	108,838	$ 125,701	$ 102,709	93,214	$ 108,680	$ 89,476	337,248	291,370
Less: Net income (loss) attributable to noncontrolling interest	1			(37)			24	(23)
Net income attributable to IDEXX Laboratories, Inc. stockholders	108,837			93,251			337,224	291,393
CAG
Segment Reporting Information [Line Items]
Revenue	533,130			478,097			1,589,397	1,456,417
Water
Segment Reporting Information [Line Items]
Revenue	34,906			33,108			99,980	94,909
LPD
Segment Reporting Information [Line Items]
Revenue	31,370			29,420			95,980	96,658
Other
Segment Reporting Information [Line Items]
Revenue	5,897			4,823			16,105	15,872
Operating Segments | CAG
Segment Reporting Information [Line Items]
Revenue	533,130			478,097			1,589,397	1,456,417
Income (loss) from operations	124,490			102,241			384,095	332,435
Operating Segments | Water
Segment Reporting Information [Line Items]
Revenue	34,906			33,108			99,980	94,909
Income (loss) from operations	17,045			15,874			47,394	43,458
Operating Segments | LPD
Segment Reporting Information [Line Items]
Revenue	31,370			29,420			95,980	96,658
Income (loss) from operations	4,994			4,007			17,637	13,439
Operating Segments | Other
Segment Reporting Information [Line Items]
Revenue	5,897			4,823			16,105	15,872
Income (loss) from operations	1,379			443			3,657	2,071
Unallocated Amounts
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (8,106)			$ (5,215)			$ (15,568)	$ (15,415)