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Financial Instruments - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 29, 2019 | Sep. 30, 2018 | Sep. 29, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Financial Instruments and Fair Value [Line Items] |  |  |  |  |
Available-for-sale securities, realized gain | $ 500,000 | $ 200,000 | $ 700,000 | $ 600,000 |
Available-for-sale securities, realized loss |  |  | 200,000 | 1,600,000 |
Available-for-sale marketable securities, Fair Market Value of Investments in debt securities with Unrealized Losses | 60,747,000 |  | 60,747,000 |  | $ 191,978,000
Fair market value of investments with unrealized losses greater than one year | 4,900,000 |  | 4,900,000 |  | 28,500,000
Aggregate loss of investments with unrealized losses greater than one year | 100,000 |  | 100,000 |  | 1,600,000
Fair market value of investments with unrealized losses less than one year | 55,800,000 |  | 55,800,000 |  | 163,500,000
Aggregate loss of investments with unrealized losses less than one year | 100,000 |  | 100,000 |  | 1,400,000
Unrealized Gain (loss) on contracts | 1,500,000 | 3,700,000 | 3,400,000 | 1,200,000 |
Equity securities unrealized gain loss |  | $ 1,000,000.0 |  | $ 1,400,000 |
Equity securities unrealized gain | 100,000 |  | 3,800,000 |  |
Equity securities unrealized loss | 200,000 |  | 200,000 |  |
Debt Mutual Funds |  |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |  |
Available for sale securities with out contractual maturity date | 4,000,000.0 |  | 4,000,000.0 |  |
Mobile Industrial Robots (MiR) |  |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |  |
Maximum amount of contingent consideration paid for acquisition | $ 81,000,000.0 |  | 81,000,000.0 |  |
Foreign Exchange Contracts |  |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |  |
Unrealized Gain (loss) on contracts |  |  | $ 114,900,000 |  | $ 163,100,000

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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
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- Definition Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), without single maturity date and not allocated over maturity grouping. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27198-111563 + Details
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- Definition Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455 + Details
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