CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 108,838	$ 93,214	$ 337,248	$ 291,370
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(13,912)	(1,845)	(12,231)	(18,172)
Unrealized gain on net investment hedge, net of tax expense of $947 and $1,105 in 2019 and $175 and $888 in 2018	3,007	555	3,507	2,818
Unrealized (loss) gain on investments, net of tax (benefit) expense of $(21) and $93 in 2019 and $12 and $61 in 2018	(67)	37	295	187
Unrealized gain (loss) on derivative instruments:
Unrealized gain, net of tax expense of $1,973 and $2,335 in 2019 and $62 and $1,846 in 2018	8,473	1,728	10,451	7,514
Reclassification adjustment for (gain) loss included in net income, net of tax (expense) benefit of $(688) and $(1,295) in 2019 and $(153) and $476 in 2018	(2,483)	(103)	(5,796)	1,936
Unrealized gain on derivative instruments	5,990	1,625	4,655	9,450
Other comprehensive (loss) gain, net of tax	(4,982)	372	(3,774)	(5,717)
Comprehensive income	103,856	93,586	333,474	285,653
Less: Comprehensive income (loss) attributable to noncontrolling interest	1	(37)	24	(23)
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 103,855	$ 93,623	$ 333,450	$ 285,676