Summary of Significant Accounting Policies Activity of financial instruments with significant Level 3 inputs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Embedded Derivative Financial Instruments [Member]
Schedule of financial instrument activity [Line Items]
Liability Balance	$ 392	$ 2,282	$ 0
Convertible redeemable Series E preferred stock and warrants issued		2,131
Change in fair value recorded in earnings	(1,890)	151
Warrant [Member]
Schedule of financial instrument activity [Line Items]
Liability Balance	83	290	36
Convertible redeemable Series E preferred stock and warrants issued		266
Change in fair value recorded in earnings	$ (207)	$ (12)

The amount recognized in earnings related to the change in fair value during the period of derivative or nonderivative instruments designated as fair value hedging instruments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration