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Financial Instruments - Additional Information (Detail) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Nov. 13, 2019
Financial Instruments and Fair Value [Line Items] |  |  |  |
Available-for-sale securities, realized gain | $ 1,300,000 | $ 4,000,000.0 | $ 1,100,000 |
Available-for-sale securities, realized loss | 200,000 | 1,600,000 | 300,000 |
Available-for-sale marketable securities, Fair Market Value of Investments in debt securities with Unrealized Losses | 23,999,000 | 191,978,000 |  |
Fair market value of investments with unrealized losses greater than one year |  | 28,500,000 |  |
Aggregate loss of investments with unrealized losses greater than one year |  | 1,600,000 |  |
Fair market value of investments with unrealized losses less than one year |  | 163,500,000 |  |
Aggregate loss of investments with unrealized losses less than one year | 23,600,000 | 1,400,000 |  |
Unrealized Gain (loss) on contracts | 1,600,000 | 2,500,000 | $ (2,900,000) |
Equity securities unrealized gain | 5,300,000 | 1,400,000 |  |
Equity securities unrealized loss | $ 400,000 | $ 7,400,000 |  |
Accounts Receivable | Customer 1 | Minimum |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Concentration risk, percentage | 10.00% |  |  |
Accounts Receivable | Customer 2 | Minimum |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Concentration risk, percentage |  | 10.00% |  |
Debt Mutual Funds |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Available for sale securities with out contractual maturity date | $ 6,900 |  |  |
Mobile Industrial Robots (MiR) |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Maximum amount of contingent consideration paid for acquisition | 63,200,000 |  |  |
Autoguide LLC [Member] |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Maximum amount of contingent consideration paid for acquisition | 106,900,000 |  |  | $ 106,900,000
Foreign Exchange Contracts |  |  |  |
Financial Instruments and Fair Value [Line Items] |  |  |  |
Unrealized Gain (loss) on contracts | $ 300,000 | $ 400,000 |  |

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