Liquidity Risks and Management's Plans (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	May 01, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Liquidity Risks and Management's Plans (MBT to update) [Abstract]
Cash and cash equivalents	$ 26,370,000		$ 26,892,000	$ 54,802,000	$ 10,189,000
Accounts Payable and Other Accrued Liabilities	7,000,000
Stockholders' Equity [Line Items]
Common stock issued during the period (in shares)	37,600,000
Closing market price of common stock		$ 1.68
Class of Warrant or Right [Line Items]
First disbursement under loan facility	10,000,000
Cash interest rate under loan facility (in hundredths)	8.75%
Interest accrued and paid	100,000
Exercise price of warrants (in dollars per share)	$ 2.81
Number of Warrant Shares Issuable (in shares)	10,300,000
Common stock, shares authorized (in shares)	100,000,000		100,000,000
Common stock reserved for future issuance (in shares)	37,600,000
Closing market price (in dollars per share)	$ 0
Period to sell common stock under ATM Program	3 years
Deerfield Management Company [Member]
Class of Warrant or Right [Line Items]
First disbursement under loan facility	10,000,000
Exercise of warrants to purchase common stock upon execution (in shares)	2,300,000
Amount to be raised incase of exercise of warrants	19,700,000
Exercise price of warrants (in dollars per share)	$ 2.81
Proceeds from secured loan	30,000,000
Proceeds from secured loan upon execution of the agreement	10,000,000
Additional Proceeds from secured loan	20,000,000
Five Year Warrant [Member]
Class of Warrant or Right [Line Items]
Number of Warrant Shares Issuable (in shares)	4,948,750
Potential value of common stock issuable upon exercise of warrants, maximum	13,900,000
Exercise price of warrants post registered public offering (in dollars per share)	$ 2.80
Minimum [Member] | Five Year Warrant [Member]
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)	$ 2.80
Maximum [Member] | Five Year Warrant [Member]
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)	$ 3.20
ATM Program [Member]
Stockholders' Equity [Line Items]
Gross proceeds	25,000,000
Percentage of gross proceeds (in hundredths)	3.00%
June 2010 CEFF [Member]
Stockholders' Equity [Line Items]
Common stock issued during the period (in shares)	1,100,000
Value of potential common stock available for issue	$ 1,700,000
Class of Warrant or Right [Line Items]
Common stock reserved for future issuance (in shares)	1,100,000