| Income Tax Disclosure [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
|---|
Income Tax Disclosure [Abstract] | |
Schedule of Components of Income Taxes |
|
|
|
December 31,
|
|
|
|
|
2016
|
|
|
2015
|
|
|
2014
|
|
|
Current:
|
|
|
|
|
|
|
|
|
|
|
Federal
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
State
|
|
|
1
|
|
|
|
1
|
|
|
|
1
|
|
|
Foreign
|
|
|
—
|
|
|
|
—
|
|
|
|
—
|
|
|
Total current
|
|
|
1
|
|
|
|
1
|
|
|
|
1
|
|
|
Deferred:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Federal
|
|
|
(20,942
|
)
|
|
|
(11,080
|
)
|
|
|
(9,046
|
)
|
|
State
|
|
|
8,936
|
|
|
|
(3,250
|
)
|
|
|
(2,689
|
)
|
|
Foreign
|
|
|
—
|
|
|
|
—
|
|
|
|
—
|
|
|
Total deferred
|
|
|
(12,006
|
)
|
|
|
(14,330
|
)
|
|
|
(11,735
|
)
|
|
Valuation allowance
|
|
|
12,006
|
|
|
|
14,330
|
|
|
|
11,735
|
|
|
Total provision for income taxes
|
|
$
|
—
|
|
|
$
|
—
|
|
|
$
|
—
|
|
|
Components of Deferred Tax Assets |
|
|
|
December 31,
|
|
|
|
|
2016
|
|
|
2015
|
|
|
Deferred tax assets:
|
|
|
|
|
|
|
|
Net operating loss carryforwards
|
|
$
|
44,909
|
|
|
$
|
37,576
|
|
|
Tax credits
|
|
|
4,084
|
|
|
|
3,023
|
|
|
Intangible assets
|
|
|
1,470
|
|
|
|
2,033
|
|
|
Capitalized R&D
|
|
|
40,297
|
|
|
|
35,514
|
|
|
Other
|
|
|
1,677
|
|
|
|
2,285
|
|
|
Total deferred tax assets
|
|
|
92,437
|
|
|
|
80,431
|
|
|
Deferred tax liabilities
|
|
|
—
|
|
|
|
—
|
|
|
Valuation allowance
|
|
|
(92,437
|
)
|
|
|
(80,431
|
)
|
|
Net deferred tax asset
|
|
$
|
—
|
|
|
$
|
—
|
|
|
Reconciliation of Effective Tax Rate |
|
|
|
2016
|
|
|
2015
|
|
|
2014
|
|
|
Statutory rate
|
|
|
34
|
%
|
|
|
34
|
%
|
|
|
34
|
%
|
|
State tax
|
|
|
(9
|
)%
|
|
|
6
|
%
|
|
|
6
|
%
|
|
Tax credit
|
|
|
1
|
%
|
|
|
2
|
%
|
|
|
1
|
%
|
|
Deemed dividend and warrant liability revaluation
|
|
|
(4
|
)%
|
|
|
—
|
%
|
|
|
—
|
%
|
|
Stock based compensation
|
|
|
(4
|
)%
|
|
|
(1
|
)%
|
|
|
(1
|
)%
|
|
Valuation allowance
|
|
|
(18
|
)%
|
|
|
(41
|
)%
|
|
|
(40
|
)%
|
|
Effective tax rates
|
|
|
0
|
%
|
|
|
0
|
%
|
|
|
0
|
%
|
|
Summary of Net Operating Losses and Carryforwards |
|
|
|
Amount
|
|
Expiration Years
|
|
Net operating losses—federal
|
|
$
|
117,090
|
|
Beginning 2024
|
|
Net operating losses—state
|
|
$
|
89,251
|
|
Beginning 2017
|
|
Tax return credits—federal
|
|
$
|
2,342
|
|
Beginning 2032
|
|
Tax return credits—state
|
|
$
|
2,640
|
|
Do not expire
|
|
Schedule of Unrecognized Tax Benefits |
|
|
|
Amount
|
|
|
Balance as of December 31, 2013
|
|
|
828
|
|
|
Additions based on tax positions related to prior year
|
|
|
—
|
|
|
Additions based on tax positions related to current year
|
|
|
171
|
|
|
Balance as of December 31, 2014
|
|
$
|
999
|
|
|
Additions based on tax positions related to prior year
|
|
|
—
|
|
|
Additions based on tax positions related to current year
|
|
|
269
|
|
|
Balance as of December 31, 2015
|
|
$
|
1,268
|
|
|
Deductions based on tax positions related to prior year
|
|
|
(27
|
)
|
|
Additions based on tax positions related to current year
|
|
|
420
|
|
|
Balance as of December 31, 2016
|
|
$
|
1,661
|
|
|