Stockholders' Equity (Details) (USD $)	6 Months Ended			6 Months Ended
	Jun. 30, 2012	Jul. 31, 2012	Dec. 31, 2011	Jun. 30, 2012 Committed Equity Financing Facility [Member]	May 31, 2012 Committed Equity Financing Facility [Member]	May 25, 2012 Committed Equity Financing Facility [Member]	Nov. 07, 2009 Committed Equity Financing Facility [Member]	Dec. 15, 2011 Shelf Registration Statement [Member]	Jun. 30, 2010 Shelf Registration Statement [Member]	Jun. 01, 2010 Shelf Registration Statement [Member]	Jun. 30, 2012 Atm Program [Member]	Jun. 15, 2012 Atm Program [Member]	Dec. 31, 2011 Atm Program [Member]
Stockholders' Equity (Textual) [Abstract]
Common Stock Purchase by Kingsbridge						3,327,000
Common Stock Shares, Purchase by Kingsbridge						$ 45,000,000
Common Stock shares issued for warrants exercisable							200,000
Common Stock shares issued for warrants, Exercise Price							$ 11.35
Contractual Term of Warrant	5 years			5 years
Common Stock Shares unsold on termination of CEFF					1,095,315
Legal, accounting, and other costs associated with CEFF agreement				62
Warrants Outstanding				200,000
Aggregate Initial Offering Price on Self Registration Statement										75,000,000
Public Offering Of Common Stock Shares under underwriting agreement								5,000,000	2,200,000
Initial Public offering price Per Share								$ 3.25	$ 7.50
Gross proceeds from sale of common stock										16,300,000	700,000	20,000,000
Net Proceeds From Sale of Common Stock										15,000,000
Amount Available Under Shelf Registration Statement											$ 22,200,000		$ 42,200,000
Common stock, shares issued	30,332,217	30,519,319	30,307,538								187,102
Stockholders Equity (Additional Textual) [Abstract]
Preferred stock, par value	$ 0.10
Preferred stock, shares authorized	10,000,000
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Common stock, par value	$ 0.001
Common stock, shares authorized	45,000,000
Common stock, shares outstanding	30,332,217	30,519,319	30,307,538