Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 313,775	$ 216,021
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,062,190	1,015,717
Derivative assets	30	528
Total	1,062,220	1,016,245
Contingent consideration	49,737	39,705
Derivative liabilities	222	203
Total	49,959	39,908
Fair Value, Measurements, Recurring \| Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	345,312	311,975
Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	380,119	461,949
Fair Value, Measurements, Recurring \| U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Fair Value, Measurements, Recurring \| Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Fair Value, Measurements, Recurring \| Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Fair Value, Measurements, Recurring \| Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
Fair Value, Measurements, Recurring \| U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Fair Value, Measurements, Recurring \| Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Fair Value, Measurements, Recurring \| Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Fair Value, Measurements, Recurring \| Equity Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale equity securities	22,984	25,772
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	701,519	754,920
Total	701,519	754,920
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	345,312	311,975
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	326,347	410,285
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Equity Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale equity securities	22,984	25,772
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	360,671	260,797
Derivative assets	30	528
Total	360,701	261,325
Derivative liabilities	222	203
Total	222	203
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	53,772	51,664
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	49,737	39,705
Total	$ 49,737	$ 39,705

Cash and cash equivalents and available for sale securities fair value disclosure.

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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