Business Combinations and Asset Purchases (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Jan. 01, 2023 USD ($) employees	Jan. 02, 2022 USD ($) employees $ / shares shares	Sep. 17, 2021 $ / shares
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability, Current	$ (11,000)
Business Combination, Contingent Consideration, Liability, Noncurrent	29,000
Business Combination, Contingent Consideration, Liability, Total	$ (40,000)
Business Combination, Contingent Consideration Arrangements, Maximum Period	7 years 10 months 24 days
Beginning balance	$ 6,533,550	$ 6,481,768	$ 6,627,119
Business Combination, Contingent Consideration Arrangements, Weighted Average Period	5 years
Business Combination, Acquisition Related Costs	$ 69,200	$ 39,800	$ 62,800
Analytical, Food and Enterprise Services businesses
Business Acquisition [Line Items]
Divestiture-related Rebranding Costs	34,300
Divestiture-related Interest and Other Expense	19,900
Foreign Currency Transaction Loss, before Tax	24,100
Divestiture-related Interest Income	(4,200)
Oxford Immunotec
Business Acquisition [Line Items]
Entity Number of Employees | employees			275
Nexcelom Bioscience
Business Acquisition [Line Items]
Entity Number of Employees | employees		130
BioLegend [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue			$ 4,056,122
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets			184,704
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			147,200
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets			9,330
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net			5,688,964
Business Acquisition, Cost of Acquired Entity, Cash Paid			3,336,115
Business Combination, Consideration Transferred, Liabilities Incurred			$ 6,857
Weighted average amortization period (in years)			16 years 3 months 18 days
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual		$ 91,700
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			$ 25,800
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value			0
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			$ 0
Entity Number of Employees | employees			700
Beginning balance			$ 3,509,931
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total			(668,919)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			(37,461)
Cash Acquired from Acquisition			292,400
Cash Acquired			(292,377)
Business Combination, Consideration Transferred			5,688,964
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax			$ 947,387
Business Acquisition, Pro Forma Earnings Per Share, Basic | $ / shares			$ 7,270
Business Acquisition, Pro Forma Earnings Per Share, Diluted | $ / shares			$ 7,250
Cash Acquired from Acquisition			$ (292,400)
Business Acquisition, Cost of Acquired Entity, Consideration Paid in Common Stock			$ 2,600,000
Business Acquisition, Share Price | $ / shares				$ 187.56
Stock Issued During Period, Shares, Acquisitions | shares			14,066,799
Business Combination, Acquisition Related Costs, Excluded From Proforma Income (Loss) From Continuing Operations			$ 43,200
Business Combination, Bridge Financing and Debt Pre-issuance Hedging Costs, Excluded From Proforma Income (Loss) From Continuing Operations			23,300
Business Combination, Pro Forma Information, Amortization of Acquired Intangible Assets			47,000
Business Acquisition, Cost of Acquired Entity, Consideration Paid in Cash			3,300,000
Acquisition-related stock compensation expense	20,000	$ 26,500	6,900
Acquisition-related Interest and Other Expense			18,000
Foreign Currency Transaction Gain, before Tax			(5,400)
Acquisition-related Bridge Financing and Debt Pre-issuance Hedging Costs			23,400
Fiscal Year 2021 Acquisitions (Excluding BioLegend) [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets			71,840
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			(4,628)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			26,507
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets			15,527
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net			981,698
Business Acquisition, Cost of Acquired Entity, Cash Paid			1,128,584
Business Combination, Consideration Transferred, Liabilities Incurred			$ 2,910
Weighted average amortization period (in years)			12 years 4 months 24 days
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value			$ (45,031)
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			183
Beginning balance			545,262
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total			(80,923)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Deferred Revenue			1,197
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt			(61,925)
Cash Acquired			(195,010)
Business Combination, Consideration Transferred			981,698
Sirion, Qognit, Sonovol and Prisms [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	98,000
Fiscal Year 2022 Acquisitions
Business Acquisition [Line Items]
Weighted average amortization period (in years)		5 years
Diagnostics [Member]
Business Acquisition [Line Items]
Beginning balance	$ 1,945,612	$ 1,930,193	1,970,350
United States of America, Dollars | Fiscal Year 2021 Other Acquisitions
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			318,600
United States of America, Dollars | Oxford Immunotec
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			590,900
United States of America, Dollars | Nexcelom Bioscience
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			267,300
United States of America, Dollars | BioLegend [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			5,700,000
United States of America, Dollars | Fiscal Year 2021 Acquisitions (Excluding BioLegend) [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments			$ 1,200,000
United States of America, Dollars | Fiscal Year 2022 Acquisitions
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments		$ 13,300