Statements of Stockholders' Equity (Deficit) (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Expenses with issuance of common stock	$ 72	$ 137	$ 1,013
Expenses with private placement financing	1,703
Lincoln Park Capital Fund, LLC [Member]
Expenses with issuance of common stock		552
Common Stock [Member]
Expenses with issuance of common stock	72	137	1,013
Expenses with issuance of common stock	55
Common Stock [Member] | Lincoln Park Capital Fund, LLC [Member]
Expenses with issuance of common stock		552
Preferred Stock [Member]
Expenses with private placement financing	$ 1,703