Segment Reporting (Summary Of Segment Performance) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Revenue	$ 315,475	$ 300,954	$ 973,800	$ 911,488
Income (loss) from operations	62,912	56,096	199,136	180,926
Interest expense, net	(400)	(478)	(1,603)	(1,200)
Income before provision for income taxes	62,512	55,618	197,533	179,726
Provision for income taxes	19,639	17,122	62,606	55,970
Net income	42,873	38,496	134,927	123,756
Less: Net income (loss) attributable to noncontrolling interest	20	(11)	14	(20)
Net income attributable to IDEXX Laboratories, Inc. stockholders	42,853	38,507	134,913	123,776
CAG Segment [Member]
Segment Reporting Information [Line Items]
Revenue	262,357	248,074	808,724	748,397
Income (loss) from operations	50,651	44,296	157,337	145,137
Water Segment [Member]
Segment Reporting Information [Line Items]
Revenue	22,223	21,648	63,788	62,123
Income (loss) from operations	10,128	9,979	28,619	25,327
LPD Segment [Member]
Segment Reporting Information [Line Items]
Revenue	18,911	20,675	64,153	69,981
Income (loss) from operations	3,504	3,648	14,580	17,974
Other Segment [Member]
Segment Reporting Information [Line Items]
Revenue	11,984	10,557	37,135	30,987
Income (loss) from operations	(119)	34	669	(207)
Unallocated Amounts [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	$ (1,252)	$ (1,861)	$ (2,069)	$ (7,305)