Business Combinations and Asset Purchases (Narrative) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Jan. 03, 2016
Business Acquisition [Line Items]
Revenue	$ 805,496,000	$ 706,923,000	$ 722,517,000	$ 648,737,000	$ 756,349,000	$ 674,313,000	$ 703,362,000	$ 643,972,000	$ 2,883,673,000	$ 2,777,996,000
Business Combination, Contingent Consideration, Liability, Current	(20,800,000)				(67,000,000.0)				(20,800,000)	(67,000,000.0)
Business Combination, Contingent Consideration, Liability, Noncurrent	14,700,000				2,700,000				14,700,000	2,700,000
Business Combination, Contingent Consideration, Liability, Total	(35,500,000)				(69,700,000)				$ (35,500,000)	(69,700,000)
Business Combination, Contingent Consideration Arrangements, Maximum Period									3 years
Business Combination, Contingent Consideration Arrangements, Description									Contingent consideration is measured at fair value at the acquisition date using projected milestone dates, discount rates, probabilities of success and projected revenues (for revenue-based considerations). The expected maximum earnout period for an acquisition with open contingency period do not exceed 1.75 years from the acquisition date, and the remaining weighted average expected earnout period at December 29, 2019 was 11 months.
Goodwill	3,111,227,000				2,952,608,000				$ 3,111,227,000	2,952,608,000	$ 3,002,198,000
Number of Years in Measurement Period from Acquisition Date to Change Underlying Assumptions									1 year
Business Combination, Contingent Consideration Arrangements, Weighted Average Period									1 year 2 months 12 days
Business Combination, Acquisition Related Costs									$ 6,600,000	15,800,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	57,100,000								57,100,000
Foreign Currency Transaction Gain (Loss), before Tax									(6,500,000)	9,400,000	29,200,000
Interest Expense									63,627,000	66,976,000	$ 43,940,000
Fiscal Year 2019 Acquisitions [Member]
Business Acquisition [Line Items]
Operating Income (Loss) From Immaterial Acquisitions									$ 0
Weighted average amortization period (in years)									11 years
Fiscal Year 2019 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	4,042,000								$ 4,042,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(2,698,000)								(2,698,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	727,000								727,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	481,000								481,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	45,282,000								45,282,000
Business Acquisition, Cost of Acquired Entity, Cash Paid									45,042,000
Business Combination, Consideration Transferred, Liabilities Incurred									638,000
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value									(634,000)
Goodwill	17,006,000								17,006,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total	(6,658,000)								(6,658,000)
Working capital and other adjustments									302,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	(3,295,000)								(3,295,000)
Cash Acquired									(1,334,000)
Business Combination, Consideration Transferred									45,282,000
Shandong Meizheng [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	15,160,000								15,160,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(706,000)								(706,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	6,278,000								6,278,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	32,000								32,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	164,399,000								164,399,000
Business Acquisition, Cost of Acquired Entity, Cash Paid									145,000,000
Business Combination, Consideration Transferred, Liabilities Incurred									6,446,000
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value									(12,100,000)
Goodwill	81,457,000								81,457,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total	(21,231,000)								(21,231,000)
Working capital and other adjustments									2,961,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	(10,991,000)								(10,991,000)
Cash Acquired									(2,108,000)
Business Combination, Consideration Transferred									164,399,000
Cisbio Bioassays SAS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	43,554,000								43,554,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	0								0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	4,835,000								4,835,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	100,000								100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	207,391,000								207,391,000
Business Acquisition, Cost of Acquired Entity, Cash Paid									219,795,000
Business Combination, Consideration Transferred, Liabilities Incurred									0
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value									0
Goodwill	72,341,000								72,341,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total	(34,886,000)								(34,886,000)
Working capital and other adjustments									138,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	(12,553,000)								(12,553,000)
Cash Acquired									(12,542,000)
Business Combination, Consideration Transferred									207,391,000
Foreign Currency Transaction Gain (Loss), before Tax									2,600,000
Fiscal Year 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Operating Income (Loss) From Immaterial Acquisitions										0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	4,905,000								4,905,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities					(461,000)					(461,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment					1,166,000					1,166,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets	776,000								776,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net					104,633,000					104,633,000
Business Acquisition, Cost of Acquired Entity, Cash Paid										95,950,000
Business Combination, Consideration Transferred, Liabilities Incurred										$ 3,354,000
Weighted average amortization period (in years)										11 years 2 months 12 days
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value										$ (6,200,000)
Goodwill	65,886,000								65,886,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total	(9,049,000)								(9,049,000)
Working capital and other adjustments									261,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	(3,881,000)								(3,881,000)
Cash Acquired										(1,132,000)
Business Combination, Consideration Transferred										104,633,000
Interest Expense										700,000
Business Combination, Increase (Decrease) in Liabilities Assumed									(400,000)
Business Combination, Increase (Decrease) in Deferred Tax Liabilities									5,100,000
Goodwill, Purchase Accounting Adjustments									6,100,000
Business Combination, Increase (Decrease) in Other Assets									(100,000)
Business Combination, Increase (Decrease) in Current Assets									(1,600,000)
Tulip Diagnostics Private Limited [Member]
Business Acquisition [Line Items]
Weighted average amortization period (in years)											11 years 9 months 18 days
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											$ 127,300,000
Compensation Expense, Excluding Cost of Good and Service Sold									500,000	6,900,000
Foreign Currency Transaction Gain (Loss), before Tax										(700,000)
EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired											99.98%
Business Acquisition, Pro Forma Revenue											$ 2,562,580,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets											121,174,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities											(61,357,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment											109,859,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets											71,621,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net											1,388,095,000
Intangible Assets, Gross (Excluding Goodwill)											907,400,000
Business Acquisition, Cost of Acquired Entity, Cash Paid											1,413,113,000
Business Combination, Consideration Transferred, Liabilities Incurred											$ 0
Weighted average amortization period (in years)											16 years 1 month 6 days
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual											$ 13,500,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual											(1,000,000.0)
Business Acquisition, Transaction Costs											9,800,000
Goodwill											591,304,000
Goodwill, Acquired During Period											591,300,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total											(251,886,000)
Working capital and other adjustments											0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt											(100,020,000)
Cash Acquired											(25,018,000)
Business Combination, Consideration Transferred											1,388,095,000
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax											$ 143,459,000
Business Acquisition, Pro Forma Earnings Per Share, Basic											$ 1.31
Business Acquisition, Pro Forma Earnings Per Share, Diluted											$ 1.29
Fiscal Year 2017 Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											$ 142,000,000.0
Fiscal Year 2017 Other Acquisitions [Member]
Business Acquisition [Line Items]
Aggregate Revenue from Immaterial Acquisitions											38,500,000
Operating Income (Loss) From Immaterial Acquisitions											0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets											16,268,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities											0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment											11,356,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets											1,691,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net											139,602,000
Business Acquisition, Cost of Acquired Entity, Cash Paid											140,861,000
Business Combination, Consideration Transferred, Liabilities Incurred											1,273,000
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											14,700,000
Goodwill											75,250,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities, Total											(15,735,000)
Working capital and other adjustments											(93,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt											(8,328,000)
Cash Acquired											(2,439,000)
Business Combination, Consideration Transferred											139,602,000
Vanadis Diagnostics AB [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value									(19,000,000.0)			$ 56,900,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High												$ 93,000,000.0
Core Technology [Member] | Fiscal Year 2019 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	27,667,000								27,667,000
Core Technology [Member] | Shandong Meizheng [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	36,500,000								36,500,000
Core Technology [Member] | Cisbio Bioassays SAS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	90,000,000								90,000,000
Core Technology [Member] | Fiscal Year 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	31,956,000								31,956,000
Core Technology [Member] | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											160,000,000
Core Technology [Member] | Fiscal Year 2017 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											12,400,000
Trade Names [Member] | Fiscal Year 2019 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	1,310,000								1,310,000
Trade Names [Member] | Shandong Meizheng [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	4,900,000								4,900,000
Trade Names [Member] | Cisbio Bioassays SAS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	5,000,000								5,000,000
Trade Names [Member] | Fiscal Year 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles					1,070,000					1,070,000
Trade Names [Member] | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											36,000,000
Trade Names [Member] | Fiscal Year 2017 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											3,000,000
Customer Relationships [Member] | Fiscal Year 2019 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	6,700,000								6,700,000
Customer Relationships [Member] | Shandong Meizheng [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	53,000,000								53,000,000
Customer Relationships [Member] | Cisbio Bioassays SAS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	39,000,000								39,000,000
Customer Relationships [Member] | Fiscal Year 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	10,200,000								10,200,000
Customer Relationships [Member] | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											710,000,000
Customer Relationships [Member] | Fiscal Year 2017 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											43,700,000
In Process Research and Development [Member] | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											1,400,000
In Process Research and Development [Member] | Fiscal Year 2017 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles											0
Diagnostics [Member]
Business Acquisition [Line Items]
Goodwill	1,612,407,000				1,617,616,000				1,612,407,000	1,617,616,000	1,657,963,000
Discovery & Analytical Solutions [Member]
Business Acquisition [Line Items]
Goodwill	1,498,820,000				$ 1,334,992,000				1,498,820,000	$ 1,334,992,000	1,344,235,000
Euro Member Countries, Euro | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											1,200,000,000
United States of America, Dollars | Fiscal Year 2019 Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments									433,100,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 31,800,000								31,800,000
United States of America, Dollars | Fiscal Year 2019 Other Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Liabilities Incurred, Contingent Consideration at Fair Value									(12,700,000)
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments									46,600,000
United States of America, Dollars | Shandong Meizheng [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments									166,500,000
United States of America, Dollars | Cisbio Bioassays SAS [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments									219,900,000
United States of America, Dollars | Fiscal Year 2018 Acquisitions [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments									$ 105,800,000
United States of America, Dollars | Tulip Diagnostics Private Limited [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High											25,200,000
United States of America, Dollars | EUROIMMUM [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											1,400,000,000
United States of America, Dollars | EUROIMMUM [Member] | Term Loan Credit Facility, 12 Months Maturity [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											200,000,000.0
United States of America, Dollars | EUROIMMUM [Member] | Line of Credit, Maturing August 11, 2021 [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											710,000,000.0
United States of America, Dollars | EUROIMMUM [Member] | Cash and Cash Equivalents [Member]
Business Acquisition [Line Items]
Business Acquisition, Cost of Acquired Entity, Cash Paid Including Working Capital And Other Adjustments											503,100,000
India, Rupees | Tulip Diagnostics Private Limited [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High											$ 1,600,000,000