Schedule of Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 305,170	$ 211,596
Available-for-sale marketable securities, Unrealized Gain	8,756	4,687
Available-for-sale marketable securities, Unrealized (Loss)	(151)	(262)
Available-for-sale marketable securities, Fair Market Value	313,775	216,021
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	20,156	23,999
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	163,586	42,167
Available-for-sale marketable securities, Unrealized Gain	1,734	431
Available-for-sale marketable securities, Unrealized (Loss)	(15)	(216)
Available-for-sale marketable securities, Fair Market Value	165,305	42,382
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	18,709	17,556
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	63,774	54,124
Available-for-sale marketable securities, Unrealized Gain	70	26
Available-for-sale marketable securities, Unrealized (Loss)	0	(1)
Available-for-sale marketable securities, Fair Market Value	63,844	54,149
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	0	1,391
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	56,672	93,267
Available-for-sale marketable securities, Unrealized Gain	6,682	4,081
Available-for-sale marketable securities, Unrealized (Loss)	(136)	(41)
Available-for-sale marketable securities, Fair Market Value	63,218	97,307
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,447	2,009
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	9,498	4,751
Available-for-sale marketable securities, Unrealized Gain	8
Available-for-sale marketable securities, Fair Market Value	9,506	4,751
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	4,353	9,942
Available-for-sale marketable securities, Unrealized Gain	72	14
Available-for-sale marketable securities, Unrealized (Loss)	0	(4)
Available-for-sale marketable securities, Fair Market Value	4,425	9,952
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	0	3,043
Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	6,686	6,753
Available-for-sale marketable securities, Unrealized Gain	190	135
Available-for-sale marketable securities, Fair Market Value	6,876	6,888
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	601	592
Available-for-sale marketable securities, Fair Market Value	$ 601	$ 592

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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