Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

The components of the Company’s deferred tax assets and liabilities, all of which are long-term, are as follows (in thousands):

	December 31,
	2014			2013
Deferred tax assets:
Net operating loss carryforwards	$	86,541		$	69,989
Tax credit carryforwards		22,716			18,816
Equipment, furnishings and other		14,396			11,313
Total deferred tax assets		123,653			100,118
Deferred tax liabilities		(187	)		(92	)
Net deferred tax assets		123,466			100,026
Valuation allowance		(123,466	)		(100,026	)
	$	—		$	—

Effective Income Tax Rate Reconciliation

The provision for income taxes differs from the provision computed by applying the Federal statutory rate to net loss before income taxes as follows (in thousands):

	Years ended December 31,
	2014			2013			2012
Federal benefit at statutory rate	$	(10,240	)	$	(16,145	)	$	(6,107	)
State income taxes, net of Federal taxes		(2,773	)		(1,517	)		(745	)
State credits		(990	)		(787	)		(1,555	)
Warrant liabilities		(6,477	)		6,871			941
Other permanent differences		37			14			(23	)
Provision related to change in valuation allowance		23,440			14,606			14,069
Current year tax credit		(1,300	)		(1,034	)		—
Return to provision		(1,504	)		(2,011	)		(6,578	)
Other, net		(192	)		5			—
	$	1		$	2		$	2