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Schedule of Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands | Apr. 04, 2021 | Dec. 31, 2020
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Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | $ 556,642 | $ 601,976
Available-for-sale marketable securities, Unrealized Gain | 5,072 | 9,077
Available-for-sale marketable securities, Unrealized (Loss) | (952) | (213)
Available-for-sale marketable securities, Fair Market Value | 560,762 | 610,840
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses | 65,454 | 70,418
U.S. Treasury Securities |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 155,337 | 257,132
Available-for-sale marketable securities, Unrealized Gain | 644 | 1,330
Available-for-sale marketable securities, Unrealized (Loss) | (791) | (158)
Available-for-sale marketable securities, Fair Market Value | 155,190 | 258,304
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses | 24,492 | 17,243
Commercial Paper |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 306,707 | 254,404
Available-for-sale marketable securities, Unrealized Gain | 8 | 10
Available-for-sale marketable securities, Unrealized (Loss) |  | (1)
Available-for-sale marketable securities, Fair Market Value | 306,715 | 254,413
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses | 13,996 | 12,173
Corporate Debt Securities |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 79,190 | 76,129
Available-for-sale marketable securities, Unrealized Gain | 4,340 | 7,539
Available-for-sale marketable securities, Unrealized (Loss) | (158) | (53)
Available-for-sale marketable securities, Fair Market Value | 83,372 | 83,615
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses | 25,553 | 39,896
Certificates of Deposit and Time Deposits |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 966 | 979
Available-for-sale marketable securities, Fair Market Value | 966 | 979
U.S. Government Agency Securities |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 4,581 | 4,294
Available-for-sale marketable securities, Unrealized Gain | 34 | 46
Available-for-sale marketable securities, Unrealized (Loss) | (3) | (1)
Available-for-sale marketable securities, Fair Market Value | 4,612 | 4,339
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses | 1,413 | 1,106
Debt Mutual Funds |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 9,242 | 8,413
Available-for-sale marketable securities, Unrealized Gain | 46 | 152
Available-for-sale marketable securities, Fair Market Value | 9,288 | 8,565
Non-U.S. Government Securities |  |
Schedule of Available-for-sale Securities |  |
Available-for-sale marketable securities, Cost | 619 | 625
Available-for-sale marketable securities, Fair Market Value | $ 619 | $ 625

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- Definition 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=121645371&loc=d3e27161-111563 + Details
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