Income Taxes Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Schedule of Deferred Tax Assets and Liabilities

At December 31, 2015 and 2014, the estimated deferred income tax assets and liability were comprised of the following:

	(in thousands)
	2015			2014
Deferred tax assets:
Net operating loss carry forwards	$	57,177		$	56,942
Stock—based compensation	6,706			7,636
Development costs	20,101			6,776
Other	2,108			1,301
	86,092			72,655
Deferred tax liability:
Depreciation	—			(551		)
Net deferred tax assets	86,092			72,104
Valuation allowance	(86,092		)	(72,104		)
Deferred tax assets, net	$	—		$	—

Schedule of Effective Income Tax Rate Reconciliation

The following is a reconciliation of the federal statutory tax rate to the Company’s effective tax rate:

	Year ended December 31,
	2015		2014		2013
Tax provision at federal statutory tax rate	35.0	%	35.0	%	35.0	%
State income taxes, net	(0.1	)%	—	%	(0.1	)%
Non-deductible interest	(1.2	)%	(11.3	)%	—	%
Permanent items	(2.5	)%	1.8	%	(0.3	)%
Expiration of net operating loss carry forwards	—	%	—	%	—	%
Change in valuation allowance	(31.4	)%	(25.5	)%	(34.7	)%
Other taxes	—	%	—	%	—	%
Non-includable (income) expenses	—	%	—	%	—	%
Effective tax rate	(0.2	)%	—	%	(0.1	)%