Income Taxes (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008 Internal Revenue Service	Dec. 31, 2007 Internal Revenue Service
Reconciliation between the U.S. federal statutory tax rate and effective tax rate from continuing operations
Tax at U.S. federal statutory rate (as a percent)	(35.00%)	(35.00%)	(35.00%)
Change in valuation allowance (as a percent)	35.00%	34.00%	38.00%
Permanent items (as a percent)	2.00%	1.00%	1.00%
Tax credits (as a percent)	(1.00%)		(4.00%)
Other	(1.00%)
Effective tax rate (as a percent)	0.00%	0.00%	0.00%
Reconciliation of beginning and ending amount of unrecognized tax benefits
Unrecognized tax benefits at the beginning of period	$ 1,215,000	$ 1,215,000	$ 1,171,000
Gross increase/(decrease) for tax positions of prior years	447,000		44,000
Unrecognized tax benefits balance as the ending of period	1,662,000	1,215,000	1,215,000
Unrecognized tax benefits recorded on consolidated balance sheets
Total unrecognized tax benefits	1,662,000	1,215,000	1,215,000
Amounts netted against deferred tax assets	(1,502,000)	(1,055,000)
Unrecognized tax benefits recorded on consolidated balance sheets	160,000	160,000
Portion of unrecognized tax benefits that, would affect the effective tax rate, if recognized	160,000
Additional disclosure
Interest and penalties accrued on unrecognized tax benefits	45,000
Interest recognized on unrecognized tax benefits	6,000
Income tax examination
Adjustments related to audit of the entity's income tax return				$ 0	$ 0