Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Summarized Report of Domestic Federal Statutory Tax Rates to Loss before Income Taxes from Operations

The reported amount of income tax expense (benefit) attributable to operations for the year differs from the amount that would result from applying domestic federal statutory tax rates to loss before income taxes from operations as summarized below (in thousands):

	Year Ended December 31,
	2015			2014			2013
Federal tax benefit at statutory rate	$	(7,246	)	$	(12,489	)	$	(13,469	)
State tax benefit net of federal effect		(1,243	)		(2,143	)		(2,311	)
Research and development credits		(456	)		(560	)		(532	)
Other permanent differences		8			2			14
Share-based compensation		678			414			650
Adjustment to basis in subsidiary		(10,808	)		(3,246	)		15,899
Change in valuation allowance		17,140			16,946			(357	)
Reduction of deferred tax asset attributed to expired net operating loss carryforward		1,927			1,076			106
Other		—			—			—
Total	$	—		$	—		$	—

Report of Company's Deferred Tax Assets

Significant components of our deferred tax assets are as follows (in thousands):

	December 31,
	2015			2014
Federal and state net operating loss carryforwards	$	139,874		$	130,011
Federal and state research and development credit carryforwards		16,222			15,536
Accrued liabilities		3,460			7,177
Properties and Equipment		7,740			—
Capitalized research and development costs		16,263			16,027
Other		1,842			2,092
Total deferred tax assets		185,401			170,843
Valuation allowance		(185,401	)		(170,843	)
Net deferred tax assets	$	—		$	—

Reconciliation Report of Beginning and Ending Amount of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

Balance at January 1, 2013	$	3,014
Additions based on tax positions taken during a prior period		—
Reductions based on tax positions taken during a prior period		(231	)
Additions based on tax positions taken during the current period		36
Reductions based on tax positions taken during the current period		—
Reductions related to settlement of tax matters		—
Reductions related to a lapse of applicable statute of limitations		—
Balance at December 31, 2013		2,819
Additions based on tax positions taken during a prior period		—
Reductions based on tax positions taken during a prior period		—
Additions based on tax positions taken during the current period		113
Reductions based on tax positions taken during the current period		—
Reductions related to settlement of tax matters		—
Reductions related to a lapse of applicable statute of limitations		—
Balance at December 31, 2014		2,932
Additions based on tax positions taken during a prior period		87
Reductions based on tax positions taken during a prior period		—
Additions based on tax positions taken during the current period		95
Reductions based on tax positions taken during the current period		—
Reductions related to settlement of tax matters		—
Reductions related to a lapse of applicable statute of limitations		—
Balance at December 31, 2015	$	3,114