BUSINESS COMBINATIONS AND DIVESTITURE - Purchase Price Allocations (Details) - USD ($) $ in Thousands	Dec. 28, 2019	Aug. 28, 2019	Apr. 29, 2019	Dec. 29, 2018	Apr. 03, 2018	Jan. 11, 2018	Dec. 30, 2017	Aug. 04, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,540,565			$ 1,247,133			$ 804,906
Citoxlab
Business Acquisition [Line Items]
Acquired trade receivables, contractual amount			$ 35,405
Trade receivables			35,405
Inventories			5,282
Other current assets (excluding cash)			13,917
Property, plant and equipment			88,605
Goodwill			280,711
Definite-lived intangible assets			162,400
Other long-term assets			20,163
Deferred revenue			(15,278)
Current liabilities			(46,081)
Deferred tax liabilities			(27,458)
Other long-term liabilities			(22,624)
Redeemable noncontrolling interest			(4,035)
Total purchase price allocation			$ 491,007
MPI Research
Business Acquisition [Line Items]
Acquired trade receivables, contractual amount					$ 35,073
Trade receivables					35,073
Inventories					4,463
Other current assets (excluding cash)					5,893
Property, plant and equipment					128,403
Goodwill					441,656
Definite-lived intangible assets					309,200
Other long-term assets					1,081
Deferred revenue					(23,926)
Current liabilities					(32,885)
Deferred tax liabilities					(65,945)
Other long-term liabilities					(2,213)
Total purchase price allocation					$ 800,800
KWS BioTest Limited
Business Acquisition [Line Items]
Acquired trade receivables, contractual amount						$ 1,309
Trade receivables						1,309
Other current assets (excluding cash)						99
Property, plant and equipment						1,136
Goodwill						17,660
Definite-lived intangible assets						3,647
Deferred revenue						(151)
Current liabilities						(1,575)
Other long-term liabilities						(596)
Total purchase price allocation						$ 21,529
Brains On-Line
Business Acquisition [Line Items]
Acquired trade receivables, contractual amount								$ 1,146
Trade receivables								1,146
Other current assets (excluding cash)								640
Property, plant and equipment								664
Goodwill								12,582
Definite-lived intangible assets								9,300
Other long-term assets								29
Deferred revenue								(405)
Current liabilities								(1,683)
Other long-term liabilities								(2,151)
Total purchase price allocation								$ 20,122
Other Acquisitions
Business Acquisition [Line Items]
Acquired trade receivables, contractual amount		$ 189
Trade receivables		189
Inventories		7,644
Property, plant and equipment		1,462
Goodwill		12,669
Other long-term assets		11,849
Current liabilities		(441)
Deferred tax liabilities		(1,331)
Other long-term liabilities		(238)
Redeemable noncontrolling interest		(8,740)
Total purchase price allocation		$ 23,063