Segment Reporting (Summary Of Segment Performance) (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
Income (loss) from operations	122,564	104,162	214,807	177,955
Interest expense, net	(7,979)	(7,276)	(15,485)	(14,760)
Income before provision for income taxes	114,585	96,886	199,322	163,195
Provision for income taxes	29,178	29,680	44,857	49,964
Net income	85,407	67,206	154,465	113,231
Less: Net income attributable to noncontrolling interest	50	4	89	10
Net income attributable to IDEXX Laboratories, Inc. stockholders	85,357	67,202	154,376	113,221
Depreciation and amortization			40,893	38,210
Expenditures for long-lived assets			38,566	37,868
CAG Segment [Member]
Segment Reporting Information [Line Items]
Revenue	439,948	400,223	843,175	757,862
Income (loss) from operations	108,731	91,019	188,586	152,397
Water Segment [Member]
Segment Reporting Information [Line Items]
Revenue	29,424	27,829	54,501	51,381
Income (loss) from operations	13,653	12,743	23,916	22,422
LPD Segment [Member]
Segment Reporting Information [Line Items]
Revenue	33,553	32,856	62,870	63,712
Income (loss) from operations	5,176	5,069	8,978	9,639
Other Segment [Member]
Segment Reporting Information [Line Items]
Revenue	6,015	5,661	10,415	11,164
Income (loss) from operations	768	(920)	1,161	(1,757)
Unallocated Amounts [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (5,764)	$ (3,749)	$ (7,834)	$ (4,746)