Stockholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	10 Months Ended							3 Months Ended
	Feb. 28, 2013	Mar. 31, 2013	Dec. 31, 2012	Apr. 25, 2013 Subsequent Event [Member]	Mar. 31, 2013 Shelf Registration Statement [Member]	Feb. 12, 2013 Shelf Registration Statement [Member]	Dec. 15, 2011 Shelf Registration Statement [Member]	Jun. 01, 2010 Shelf Registration Statement [Member]	Mar. 31, 2013 ATM Program [Member]	Jun. 15, 2012 ATM Program [Member]
Stockholders' Equity (Textual) [Abstract]
Aggregate initial offering price on self registration statement								$ 75
Public offering of common stock shares under underwriting agreement						6,100,000	5,000,000
Initial public offering price per share						$ 1.30	$ 3.25
Gross proceeds from sale of common stock						7.9	16.3		14.4	20.0
Net proceeds from sale of common stock						7.3	15.0		8.5
Net proceeds from issuance of common stock	7.3	13.8							13.8
Common stock, shares issued		43,037,144	32,204,720						6,600,000
Amount available under shelf registration statement					19.9
Previously allocated amount under shelf registration statement									$ 5.6
Stockholders' Equity (Additional Textual) [Abstract]
Common stock, par value		$ 0.001	$ 0.001
Common stock, shares authorized		45,000,000	45,000,000	95,000,000
Common stock, shares outstanding		43,037,144	32,204,720
Preferred stock, shares authorized		10,000,000	10,000,000
Preferred stock, par value		$ 0.10	$ 0.10
Preferred stock, shares issued
Preferred stock, shares outstanding