Revenue Recognition - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
Dec. 31, 2018 |
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| Disaggregation Of Revenue [Line Items] | |||||
| Revenue from products and services transferred to customers, percentage | 77.00% | 85.00% | 81.00% | 85.00% | |
| Revenue from services transferred to customers over time, percentage | 23.00% | 15.00% | 19.00% | 15.00% | |
| Undelivered elements (product training, installation, product and support services) | $ 566 | $ 566 | $ 730 | ||
| Revenue recognized from contract liability | 100 | $ 200 | $ 500 | $ 800 | |
| China | |||||
| Disaggregation Of Revenue [Line Items] | |||||
| Increased in allowance for doubtful accounts reserve | $ 1,100 | ||||
| X | ||||||||||
- Definition Contract with customer liability in undelivered elements. No definition available.
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| X | ||||||||||
- Definition Contract with customer liability, revenue recognized, undelivered elements. No definition available.
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| X | ||||||||||
- Definition Revenue from products and services transferred to customers at a single point in time, percentage. No definition available.
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| X | ||||||||||
- Definition Revenue from services transferred to customers over time, percentage. No definition available.
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| X | ||||||||||
- Definition Amount of increase (decrease) in allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Details
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