Income Taxes (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Reconciliation Between U.S. Statutory Income Tax Rate and Company's Effective Rate

The reconciliation between the U.S. statutory income tax rate and the Company’s effective rate consists of the following:

	Year Ended December 31,
	2016			2015			2014
U.S. federal income tax statutory rate		35	%		35	%		35	%
Permanent differences		(4	)%		(11	)%		—	%
State tax, net of federal benefit		(1	)%		(6	)%		—	%
Changes in valuation allowance for deferred tax assets		(30	)%		(11	)%		1	%
Stock-based compensation		(1	)%		(8	)%		—	%
Debt and warrant fair value adjustments		—	%		—	%		(26	)%
Write down of losses not previously benefitted		—	%		—	%		(11	)%
Other		1	%		1	%		(1	)%
Effective tax rate		—			—			—

Schedule of Deferred Tax Assets and Deferred Tax Liabilities

The tax effects of temporary differences between financial statement and tax accounting that gave rise to significant portions of the Company’s deferred tax assets and deferred tax liabilities at December 31, 2016 and 2015 are presented below:

	December 31,
	2016			2015
	(In thousands)
Deferred tax assets:
Net operating loss carryforwards	$	66,276		$	62,671
Stock-based compensation		6,140			4,938
Tax credit carryforwards		312			323
Reserves and accruals		398			140
Intangible assets and amortization		95			150
Total gross deferred tax assets		73,221			68,222
Deferred tax liabilities:
Depreciation		(5,295	)		(3,841	)
Total deferred tax liabilities		(5,295	)		(3,841	)
Total deferred tax assets and liabilities		67,926			64,381
Valuation allowance		(67,926	)		(64,381	)
Net deferred tax asset	$	—		$	—