Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Provision (Benefit)

	Years ended December 31,
	2020		2019		2018
	(In thousands)
Current:
Foreign	1,114		—		—
Total current tax provision	1,114		—		—
Deferred
Foreign	—		—		(1,250)
Total deferred tax provision (benefit)	—		—		(1,250)
Total income tax provision (benefit)	$	1,114	$	—	$	(1,250)

Schedule of Components of Loss Before Income Taxes

The following table presents domestic and foreign components of loss before provision (benefit) for income taxes:

	Years ended December 31,
	2020		2019		2018
	(In thousands)
U.S.	$	(110,327)	$	(59,426)	$	(45,024)
Foreign	(6,066)		(5,060)		(28,853)
Loss before income taxes	$	(116,393)	$	(64,486)	$	(73,877)

Schedule of Reconciliation of Income Tax Expense Computed Statutory Federal Income Tax and Financial Statements

Income tax provision (benefit) for the years ended December 31, 2020, 2019 and 2018 differed from the amounts computed by applying the statutory federal income tax rate of 21% to pretax income (loss) as a result of the following:

	Years ended December 31,
	2020		2019		2018
	(In thousands)
Federal income tax expense at statutory rate	$	(24,442)	$	(13,542)	$	(15,514)
Stock compensation	(2,787)		(1,212)		(1,512)
Non-deductible expenses	941		307		75
Other	166		298		41
Research and development tax credits	(3,150)		(948)		(1,215)
Change in valuation allowance	24,817		18,312		11,219
Foreign rate differential	595		(212)		(586)
Impact of internal reorganization	2,669		—		—
Uncertain tax positions	2,305		(6,242)		6,242
State deferred tax adjustment	—		3,239		—
Total tax provision (benefit)	$	1,114	$	—	$	(1,250)

Schedule of Deferred Tax Assets

The following table presents significant components of the Company’s deferred tax assets:

	As of December 31,
	2020		2019
	(In thousands)
Deferred tax assets:
Net operating loss carryforwards	$	74,023	$	53,309
Accruals, reserve and other	1,588		834
Tax credit carryforwards	11,727		6,008
Stock-based compensation	5,975		4,767
Intangibles	18		24
Lease obligation	6,630		6,896
Other	2		151
Total deferred tax assets before valuation allowance	99,963		71,989
Valuation allowance	(94,645)		(66,201)
Total deferred tax assets	5,318		5,788
Deferred tax liabilities:
Right-of-use assets	(4,183)		(4,483)
Property and equipment	(1,135)		(1,305)
Total deferred tax liabilities	$	(5,318)	$	(5,788)
Net deferred tax assets	$	—	$	—

Schedule of Unrecognized Tax Benefits

A reconciliation of the unrecognized tax benefits is as follows:

	Years ended December 31,
	2020		2019		2018
	(In thousands)
Unrecognized tax benefits as of the beginning of the year	$	3,558	$	8,805	$	2,745
Increase (decrease) related to prior year tax provisions	—		(6,242)		1,941
Increase related to current year tax provisions	5,119		995		4,119
Unrecognized tax benefits as of the end of the year	$	8,677	$	3,558	$	8,805