Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 582,131	$ 427,792	$ 377,047
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	15,151	(1,590)	(21,911)
Unrealized gain (loss) on Euro-denominated notes, net of tax expense (benefit) of $(2,325) in 2020, $564 in 2019 and $1,148 in 2018	(7,378)	1,790	3,917
Unrealized gain (loss) on investments, net of tax expense (benefit) of $(120) in 2020, $84 in 2019 and $(40) in 2018	(382)	267	(135)
Unrealized gain (loss) on derivative instruments:
Unrealized gain (loss) on foreign currency exchange contracts, net of tax expense (benefit) of $(2,013) in 2020, $362 in 2019 and $2,529 in 2018	(8,527)	1,196	10,659
Unrealized gain (loss) on cross currency swaps, net of tax expense of $(1,774) in 2020, $664 in 2019 and $323 in 2018	(5,626)	2,107	1,360
Less: reclassification adjustment for (gains) losses included in net income, net of tax (expense) benefit of $(158) in 2020, $(2,467) in 2019 and $187 in 2018	(671)	(8,161)	789
Unrealized (loss) gain on derivative instruments	(14,824)	(4,858)	12,808
Other comprehensive loss, net of tax	(7,433)	(4,391)	(5,321)
Comprehensive income	574,698	423,401	371,726
Less: comprehensive income attributable to noncontrolling interest	355	72	16
Comprehensive income attributable to IDEXX Laboratories, Inc.	$ 574,343	$ 423,329	$ 371,710