CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 102,709	$ 89,476
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(1,423)	5,165
Unrealized gain (loss) on net investment hedge	1,480	(2,216)
Unrealized gain on investments, net of tax expense of $128 in 2019 and $40 in 2018	407	118
Unrealized gain (loss) on derivative instruments:
Unrealized gain (loss), net of tax expense (benefit) of $531 in 2019 and $(377) in 2018	2,474	(2,388)
Reclassification adjustment for (gain) loss included in net income, net of tax (expense) benefit of $(249) in 2019 and $250 in 2018	(1,162)	1,585
Unrealized gain (loss) on derivative instruments	1,312	(803)
Other comprehensive gain, net of tax	1,776	2,264
Comprehensive income	104,485	91,740
Less: Comprehensive income attributable to noncontrolling interest	28	25
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 104,457	$ 91,715