Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Income Taxes
Period for which prior cumulative losses considered in assessing the realization of deferred tax assets		2 years
Valuation allowance	$ 7,900	$ 7,900	$ 8,800
Decreases in the valuation allowance	387	877
Net deferred tax assets	$ 0	$ 0	$ 0