Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Estimated fair values of the liabilities measured on a recurring basis
Total	$ 13,806	$ 15,270
Fair Value, Measurements, Recurring [Member]
Estimated fair values of the liabilities measured on a recurring basis
Embedded derivative liabilities	4,062	3,680
Warrant derivative liabilities	9,744	11,590
Total	13,806	15,270
Quoted Prices in Active Markets -( Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Estimated fair values of the liabilities measured on a recurring basis
Embedded derivative liabilities
Warrant derivative liabilities
Total
Significant Other Observable Inputs - (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Estimated fair values of the liabilities measured on a recurring basis
Embedded derivative liabilities
Warrant derivative liabilities
Total
Significant Unobservable Inputs - (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Estimated fair values of the liabilities measured on a recurring basis
Embedded derivative liabilities	4,062	3,680
Warrant derivative liabilities	9,744	11,590
Total	$ 13,806	$ 15,270