Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
Net operating loss carryforwards	$ 38,679	$ 37,513
Research and development credit carryforwards	10,650	10,615
Intangibles	382	395
Other	2,692	2,527
Gross deferred tax assets	52,403	51,050
Valuation allowance	(52,104)	(50,724)
Total deferred tax assets	$ 299	$ 326
Other
Total deferred tax liabilities
Net deferred tax assets	$ 299	$ 326