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Summary of Significant Accounting Policies - Additional Information (Detail) shares in Thousands, $ in Thousands |  | 12 Months Ended
--- | --- | ---
May 31, 2019 USD ($) | Dec. 31, 2020 USD ($) Customer shares | Dec. 31, 2019 USD ($) Customer shares | Dec. 31, 2018 USD ($) Customer shares
Significant Accounting Policies [Line Items] |  |  |  |
Subsidiary ownership percentage |  | 100.00% |  |
Number of customers accounted for 10% or more sales | Customer |  | 1 | 2 | 2
Depreciation and amortization of property & equipment |  | $ 13,562 | $ 12,447 | $ 11,832
Evaluation of tax benefits realized upon settlement |  | 50.00% |  |
Gain loss on disposal of subsidary |  | $ (293) | 12,409 |
Dialogue Semiconductor PLC [Member] | FCI |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Disposal group discontinued operation consideration receivable | $ 54,000 |  |  |
Gain loss on disposal of subsidary | 12,409 |  |  |
Disposal group discontinued operations net asset value | $ 39,367 |  |  |
Restricted assets net |  | $ 5,400 | 5,400 |
Escrow Deposit |  |  | $ 5,400 |
Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Short term investment maturity period |  | 3 months |  |
Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Short term investment maturity period |  | 1 year |  |
Held-to-maturity investment maturity period |  | 1 year |  |
Net sales | Customers accounted for 10% or more | Top Ten Customers [Member] |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Major customers percentage of net sales |  | 71.00% | 74.00% | 69.00%
Net sales | Customers accounted for 10% or more | Two Customers [Member] |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Major customers percentage of net sales |  | 24.00% | 31.00% | 34.00%
Employee Stock Option And Restricted Stock Units [Member] |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
The effect of dilutive securities of employee stock options and restricted stock units | shares |  | 489 | 475 | 389
Employee Stock Option And Restricted Stock Units [Member] | American Depositary Shares |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
The effect of dilutive securities of employee stock options and restricted stock units | shares |  | 123 | 119 | 97
Development technology | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Intangible asset amortized over estimated useful lives |  | 3 years 6 months |  |
Development technology | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Intangible asset amortized over estimated useful lives |  | 5 years 6 months |  |
Software | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 1 year |  |
Software | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 5 years |  |
Buildings | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 25 years |  |
Buildings | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 50 years |  |
Machinery and Equipment | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 3 years |  |
Machinery and Equipment | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 6 years |  |
Furniture and Fixtures | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 3 years |  |
Furniture and Fixtures | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 8 years |  |
Leasehold And Building Improvement | Minimum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 2 years |  |
Leasehold And Building Improvement | Maximum |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |
Property plant and equipment estimated useful life |  | 6 years |  |

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