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Balance Sheet Components (Schedule of Changes in Carrying Value of Long-term Investments) (Details) - USD ($) $ in Thousands | 9 Months Ended
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Oct. 03, 2021 | Sep. 27, 2020
Balance Sheet Related Disclosures [Abstract] |  |  |
Beginning Balance | [1] | $ 7,758 | $ 8,147
Additions from purchase of investments |  | 340 | 5,850
Disposal |  | (778) | 0
Impairment |  | (549) | (5,372)
Ending Balance | [1] | $ 6,771 | $ 8,625
[1] | The balances excluded an investment in limited partnership funds of $0.8 million, $0.4 million and $0.6 million as of October 3, 2021, September 27, 2020 and December 31, 2020, respectively. Additionally, the balance as of October 3, 2021 excluded an investment in convertible debt securities of $0.3 million.

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- Definition Amount of investment in equity security without readily determinable fair value. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117539-209714 + Details
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