Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 263,269	$ 222,054	$ 192,135
Other comprehensive income, net of tax:
Foreign currency translation adjustments	25,107	(5,874)	(30,718)
Unrealized gain (loss) on net investment hedge	(8,347)	2,142	1,894
Unrealized gain (loss) on investments, net of tax expense (benefit) of $- in 2017, $113 in 2016 and ($93) in 2015	(42)	245	(226)
Unrealized gain (loss) on derivative instruments:
Unrealized (loss) gain, net of tax (benefit) expense of ($5,304) in 2017, $2,174 in 2016 and $3,736 in 2015	(10,332)	4,950	8,839
Less: reclassification adjustment for losses (gains) included in net income, net of tax expense of $224 in 2017, $949 in 2016 and $5,853 in 2015	197	(2,251)	(13,983)
Unrealized gain (loss) on derivative instruments	(10,135)	2,699	(5,143)
Other comprehensive income (loss), net of tax	6,583	(788)	(34,194)
Comprehensive income	269,852	221,266	157,941
Less: comprehensive income attributable to noncontrolling interest	125	9	57
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 269,727	$ 221,257	$ 157,884