Nature of Business (Details Textual) (USD $)	1 Months Ended	12 Months Ended			124 Months Ended
	Oct. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012	Aug. 31, 2012	Jan. 31, 2010
Stockholders' Equity, Reverse Stock Split		one-for-5.7778
Stock Issued During Period, Shares, New Issues	5,750,000
Equity Issuance, Per Share Amount (in dollars per share)	$ 15
Proceeds from issuance of stock offerings, net of issuance costs	$ 78,700,000	$ 108,499,996	$ 0	$ 19,690,079	$ 172,477,162
Number Of Common Shares Attributable To Conversion Of Preferred Stock	7,403,817
Common stock, authorized	25,000,000	25,000,000	65,000,000		25,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001		$ 0.001
Preferred stock, authorized	5,000,000					52,777,778	27,777,778
Preferred stock, par value (in dollars per share)	$ 0.001