Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Tax Disclosure [Abstract]

Components of Provision for Income Taxes

The following table presents components of the Company’s provision for income taxes as for the period presented (in thousands):

	December 31,
	2019		2018		2017
Current expense (benefit):
Federal	$	—	$	—	$	—
State	—		—		—
Foreign	68		80		—
Total current tax expense (benefit)	68		80		—
Deferred expense (benefit):
Federal	—		—		—
State	—		—		—
Foreign	(3)		(36)		—
Total deferred tax expense (benefit)	(3)		(36)		—
Total Tax Expense (benefit)	$	65	$	44	$	—

Reconciliation of Tax Expense Computed at Statutory Federal Rate and Company's Tax Expense

The following table presents a reconciliation of the tax expense computed at the statutory federal rate and the Company’s tax expense for the period presented (in thousands):

	December 31,
	2019		2018		2017
Tax at statutory federal rate	$	(11,446)	$	(10,570)	$	(10,143)
Stock-based compensation	(5,560)		(8,557)		(7,634)
Meals and Entertainment	409		309		198
Other	614		148		(145)
Tax credits	(1,128)		(1,015)		(644)
2017 Tax Act	—		44		21,969
Change in valuation allowance	17,176		19,685		(3,601)
Provision for income taxes	$	65	$	44	$	—

Significant Components of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities are as follows (in thousands):

	December 31,
	2019		2018
Deferred tax assets:
Net operating loss carryforwards	$	64,648	$	50,601
Tax credit carryforwards	5,601		4,287
Share-based compensation	5,932		3,149
Allowances and other	11,443		8,827
Lease obligation	23,869		—
Total deferred tax assets	111,493		66,864
Valuation allowance	(88,433)		(66,435)
Net deferred tax assets	23,060		429
Deferred Tax Liabilities:
Depreciation and Amortization	(850)		(388)
Right of use asset	(22,171)		—
Total deferred tax liability	(23,021)		(388)
Total deferred tax assets	$	39	$	41

Summary of Valuation Allowance for Deferred Tax Assets

The valuation allowance for deferred tax assets consisted of the following activity for the years ended December 31, 2019, 2018 and 2017 (in thousands):

	Balance at beginning of year		Additions		Deductions		Balance at end of year
Year Ended December 31, 2017	$	44,861	$	—	$	540	$	44,321
Year Ended December 31, 2018	44,321		22,114		—		66,435
Year Ended December 31, 2019	$	66,435	$	21,998	$	—	$	88,433

Reconciliation of Unrecognized Tax Benefit

A reconciliation of the Company’s unrecognized tax benefit amount is as follows (in thousands):

	Year Ended December 31,
	2019		2018		2017
Balance at beginning of year	$	1,459	$	943	$	616
Additions for tax positions taken in current year	383		441		328
Increases in balance related to prior year tax positions	—		75		—
Decreases in balances related to prior year tax position	—		—		(1)
Balance at end of year	$	1,842	$	1,459	$	943