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Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Income Tax Disclosure [Abstract] |  |  |
Tax benefit at federal statutory rate | $ (39,948) | $ (22,081) | $ (10,972)
State income taxes | (16,570) | (4,694) |
Tax credits | (8,010) | (6,530) | (2,387)
Uncertain tax positions | 2,003 | 2,044 | 708
Stock-based compensation | 353 | 1,493 | 1,251
Nondeductible expense | 51 | 124 | 58
Tax benefit recognized on utilization of attributes previous reserved |  | (13,582) |
Deferred adjustment from amended tax return |  | (1,073) |
Change in valuation allowance | 62,280 | 44,748 | 11,346
Others | $ (159) | $ (449) | $ (4)

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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
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- Definition The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
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