Schedule of Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Sep. 29, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 414,857	$ 259,011
Available-for-sale marketable securities, Unrealized Gain	5,343	592
Available-for-sale marketable securities, Unrealized (Loss)	(105)	(2,967)
Available-for-sale marketable securities, Fair Market Value	420,095	256,636
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	60,747	191,978
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	184,229	110,969
Available-for-sale marketable securities, Unrealized Gain	847	112
Available-for-sale marketable securities, Unrealized (Loss)	(51)	(1,360)
Available-for-sale marketable securities, Fair Market Value	185,025	109,721
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	25,814	75,040
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	117,618	86,130
Available-for-sale marketable securities, Unrealized Gain	99	13
Available-for-sale marketable securities, Unrealized (Loss)	(3)	(26)
Available-for-sale marketable securities, Fair Market Value	117,714	86,117
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	30,704	85,094
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	86,718	41,133
Available-for-sale marketable securities, Unrealized Gain	4,229	432
Available-for-sale marketable securities, Unrealized (Loss)	(49)	(1,545)
Available-for-sale marketable securities, Fair Market Value	90,898	40,020
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	3,079	24,767
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	14,083	7,604
Available-for-sale marketable securities, Unrealized Gain	3
Available-for-sale marketable securities, Fair Market Value	14,086	7,604
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	8,009	9,646
Available-for-sale marketable securities, Unrealized Gain	17	1
Available-for-sale marketable securities, Unrealized (Loss)	(2)	(36)
Available-for-sale marketable securities, Fair Market Value	8,024	9,611
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,150	7,077
Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	3,820	3,153
Available-for-sale marketable securities, Unrealized Gain	148	34
Available-for-sale marketable securities, Fair Market Value	3,968	3,187
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	380	376
Available-for-sale marketable securities, Fair Market Value	$ 380	$ 376

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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