| Related Party Balances And Transactions - Schedule of Related Party Transactions (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
| Related Party Transactions [Abstract] | |||
| Revenues (net revenues) | $ (12,014) | $ 1,002 | $ 51 | 
| X | ||||||||||
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- Definition Amount of transactions with related party during the financial reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
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- References No definition available. 
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