Segment Reporting (Summary of Segment Performance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Gross profit	$ 1,571,040	$ 1,365,549	$ 1,241,542
Sales and marketing	434,435	418,193	387,406
General and administrative	300,832	261,317	244,938
Research and development	141,249	133,193	117,863
Income from operations	694,524	552,846	491,335
Revenue	2,706,655	2,406,908	2,213,242
Interest expense, net	(32,539)	(30,628)	(33,593)
Income before provision for income taxes	661,985	522,218	457,742
Provision for income taxes	79,854	94,426	80,695
Net income	582,131	427,792	377,047
Less: Net income attributable to noncontrolling interest	355	72	16
Net income attributable to IDEXX Laboratories, Inc. stockholders	581,776	427,720	377,031
Depreciation and amortization	95,998	88,011	83,178
CAG
Segment Reporting Information [Line Items]
Revenue	2,385,765	2,119,183	1,935,428
Water
Segment Reporting Information [Line Items]
Revenue	128,625	132,850	125,198
LPD
Segment Reporting Information [Line Items]
Revenue	145,845	132,635	130,581
Other
Segment Reporting Information [Line Items]
Revenue	46,420	22,240	22,035
Operating Segments | CAG
Segment Reporting Information [Line Items]
Income from operations	574,887	462,605	412,623
Revenue	2,385,765	2,119,183	1,935,428
Depreciation and amortization	84,697	77,620	72,789
Operating Segments | CAG | Restatement Adjustment
Segment Reporting Information [Line Items]
Cost of sales		(247)	(1,540)
Gross profit		247	1,540
Sales and marketing		(239)	(574)
General and administrative		13,004	3,316
Research and development		16,479	15,658
Total operating expenses		29,244	18,400
Income from operations		$ (28,997)	$ (16,860)
Operating Segments | CAG | Previously Reported
Segment Reporting Information [Line Items]
Cost of sales, percentage		0.00%	(0.10%)
Gross profit, percentage		0.00%	0.10%
Sales and marketing, percentage		0.00%	0.00%
General and administrative, percentage		0.60%	0.20%
Research and development, percentage		0.80%	0.80%
Total operating expenses, percentage		1.40%	1.00%
Income from operations, percentage		(1.40%)	(0.90%)
Operating Segments | Water
Segment Reporting Information [Line Items]
Income from operations	58,867	$ 61,923	$ 56,639
Revenue	128,625	132,850	125,198
Depreciation and amortization	2,630	2,794	2,592
Operating Segments | Water | Restatement Adjustment
Segment Reporting Information [Line Items]
Cost of sales		(11)	(69)
Gross profit		11	69
Sales and marketing		(11)	(25)
General and administrative		501	66
Research and development		33	(4)
Total operating expenses		523	37
Income from operations		$ (512)	$ 32
Operating Segments | Water | Previously Reported
Segment Reporting Information [Line Items]
Cost of sales, percentage		0.00%	(0.10%)
Gross profit, percentage		0.00%	0.10%
Sales and marketing, percentage		0.00%	0.00%
General and administrative, percentage		0.40%	0.10%
Research and development, percentage		0.00%	0.00%
Total operating expenses, percentage		0.40%	0.00%
Income from operations, percentage		(0.40%)	0.00%
Operating Segments | LPD
Segment Reporting Information [Line Items]
Income from operations	40,008	$ 24,735	$ 19,454
Revenue	145,845	132,635	130,581
Depreciation and amortization	4,070	4,007	4,094
Operating Segments | LPD | Restatement Adjustment
Segment Reporting Information [Line Items]
Cost of sales		(14)	(87)
Gross profit		14	87
Sales and marketing		(13)	(32)
General and administrative		625	81
Research and development		41	(4)
Total operating expenses		653	45
Income from operations		$ (639)	$ 42
Operating Segments | LPD | Previously Reported
Segment Reporting Information [Line Items]
Cost of sales, percentage		0.00%	(0.10%)
Gross profit, percentage		0.00%	0.10%
Sales and marketing, percentage		0.00%	0.00%
General and administrative, percentage		0.50%	0.10%
Research and development, percentage		0.00%	0.00%
Total operating expenses, percentage		0.50%	0.00%
Income from operations, percentage		(0.50%)	0.00%
Operating Segments | Other
Segment Reporting Information [Line Items]
Income from operations	20,762	$ 3,583	$ 2,619
Revenue	46,420	22,240	22,035
Depreciation and amortization	$ 4,601	3,590	3,703
Operating Segments | Other | Restatement Adjustment
Segment Reporting Information [Line Items]
Cost of sales		(6)	(35)
Gross profit		6	35
Sales and marketing		0	0
General and administrative		1,363	1,145
Research and development		0	0
Total operating expenses		1,363	1,145
Income from operations		$ (1,357)	$ (1,110)
Operating Segments | Other | Previously Reported
Segment Reporting Information [Line Items]
Cost of sales, percentage		0.00%	(0.20%)
Gross profit, percentage		0.00%	0.20%
Sales and marketing, percentage		0.00%	0.00%
General and administrative, percentage		6.10%	5.20%
Research and development, percentage		0.00%	0.00%
Total operating expenses, percentage		6.10%	5.20%
Income from operations, percentage		(6.10%)	(5.00%)
Unallocated | Previously Reported
Segment Reporting Information [Line Items]
Cost of sales		$ 278	$ 1,731
Gross profit		(278)	(1,731)
Sales and marketing		263	631
General and administrative		(15,493)	(4,608)
Research and development		(16,553)	(15,650)
Total operating expenses		(31,783)	(19,627)
Income from operations		$ 31,505	$ 17,896