Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2012 Recurring basis Quoted prices in active markets for identical assets (Level 1) Money Market Funds	Dec. 31, 2013 Recurring basis Quoted prices in active markets for identical assets (Level 1) U.S. Treasury money market funds	Dec. 31, 2012 Recurring basis Significant unobservable inputs (Level 3) Series A Warrant	Dec. 31, 2012 Recurring basis Significant unobservable inputs (Level 3) Series B Warrant
Fair Value Measurements
Investments in money market funds		$ 524	$ 203,828
Warrant Liability	$ 966			$ 523	$ 443