Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 377,047	$ 263,269	$ 222,054
Other comprehensive income, net of tax:
Foreign currency translation adjustments	(21,911)	25,107	(5,874)
Unrealized gain (loss) on net investment hedge	3,917	(8,347)	2,142
Unrealized gain (loss) on investments, net of tax expense (benefit) of ($40) in 2018, $0 in 2017 and $113 in 2016	(135)	(42)	245
Unrealized gain (loss) on derivative instruments:
Unrealized gain (loss), net of tax expense (benefit) of $2,852 in 2018, ($5,304) in 2017 and $2,174 in 2016	12,019	(10,332)	4,950
Less: reclassification adjustment for (gains) losses included in net income, net of tax (expense) benefit of $187 in 2018, $224 in 2017 and ($949) in 2016	789	197	(2,251)
Unrealized gain (loss) on derivative instruments	12,808	(10,135)	2,699
Other comprehensive income gain (loss), net of tax	(5,321)	6,583	(788)
Comprehensive income	371,726	269,852	221,266
Less: comprehensive income attributable to noncontrolling interest	16	125	9
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 371,710	$ 269,727	$ 221,257