Stockholders' Equity - Common and Preferred Shares (Details) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Summary of the Company's outstanding common stock warrants
Number of Warrants outstanding	154	154
Committed Equity Financing Facility Warrants [Member]
Summary of the Company's outstanding common stock warrants
Date of Issuance	Feb. 19, 2008
Average Exercise Price	54.80
Number of Warrants outstanding	13	13
Direct Registration Series I Warrants [Member]
Summary of the Company's outstanding common stock warrants
Date of Issuance	Jul. 20, 2009
Average Exercise Price	42.00
Number of Warrants outstanding	141	141