Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Reserve and accruals	$ 2,635	$ 1,704
Net operating loss carryforwards	46,112	26,932
Operating lease liability	9,196	1,448
Deferred revenue	14,194	13,173
Tax credits	17,423	9,569
Stock based compensation	1,892	1,049
Total gross deferred tax assets	91,452	53,875
Valuation allowance	(81,980)	(52,260)
Total deferred tax assets	9,472	1,615
Operating lease right-of-use asset	(8,805)	(1,214)
Fixed and intangible assets	(667)	(401)
Total deferred tax liabilities	$ (9,472)	$ (1,615)

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Amount of deferred tax consequences attributable to taxable temporary differences derived from fixed and intangible assets.

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Amount of deferred tax liability attributable to taxable temporary differences.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences from leasing arrangements.

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