Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details Textual)

v2.4.0.6
Fair Value Measurements (Details Textual) (USD $)
3 Months Ended
Mar. 31, 2013
Dec. 31, 2012
Fair Value Measurements (Textual) [Abstract]    
Maximum maturity period of collateralized securities 1 year  
Warrant liability $ 1,988,000 $ 3,422,000
Maximum maturity period of cash and cash equivalents 90 days  
Maximum maturity period of short-term investments 1 year  
Other than temporary impairments to investment in marketable securities $ 0