Common Stock (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Mar. 20, 2015	Jun. 30, 2014	Dec. 31, 2014	Sep. 16, 2014
Class of Stock [Line Items]
Capitalized stock issuance costs	$ 161,000		$ 161,000			$ 192,000
Amortized financing costs charged against additional paid-in capital	$ 23,000	$ 22,000	$ 45,000		$ 44,000
Common Stock [Member]
Class of Stock [Line Items]
Common shares sold in stock offering (in shares)			17
MLV & Co. LLC [Member] | At Market Issuance Sales Agreement [Member] | Common Stock [Member]
Class of Stock [Line Items]
Stock offering, maximum sales value							$ 8,000,000
Stock offering costs, commission percentage				3.00%
Common shares sold in stock offering (in shares)			17
Weighted-average selling price in common stock offering (in dollars per share)	$ 1.11		$ 1.11
Proceeds from sale of common stock			$ 19,000
Proceeds from sale of common stock, net of commissions expense			18,000
Capitalized stock issuance costs	$ 125,000		125,000
Amortized financing costs charged against additional paid-in capital			$ 100,000