Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 93,214	$ 70,514	$ 291,370	$ 224,979
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(1,845)	8,282	(18,172)	24,250
Unrealized gain (loss) on net investment hedge	555	(2,035)	2,818	(6,895)
Unrealized gain on investments, net of tax expense of $12 and $61 in 2018 and $12 and $35 in 2017	37	23	187	109
Unrealized gain (loss) on derivative instruments:
Unrealized gain (loss), net of tax expense (benefit) of $62 and $1,846 in 2018 and $(1,836) and $(5,035) in 2017	1,728	(3,090)	7,514	(8,472)
Reclassification adjustment for (gains) losses included in net income, net of tax (expense) benefit of $(153) and $476 in 2018 and $333 and $(348) in 2017	(103)	560	1,936	(587)
Unrealized gain (loss) on derivative instruments	1,625	(2,530)	9,450	(9,059)
Other comprehensive gain (loss), net of tax	372	3,740	(5,717)	8,405
Comprehensive income	93,586	74,254	285,653	233,384
Less: Comprehensive (loss) income attributable to noncontrolling interest	(37)	3	(23)	92
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 93,623	$ 74,251	$ 285,676	$ 233,292