v2.4.0.8

Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Change in the fair value of Series D Warrants
Change in fair value of warrant liability	$ 688	$ (8)	$ (33)
Recurring basis | Total
Assets:
Cash equivalents	2,438		3,357
Liabilities:
Series D redeemable convertible preferred stock warrants	814		126
Change in the fair value of Series D Warrants
Balance at the end of the period	814		126
Recurring basis | Level 1
Assets:
Cash equivalents	2,438		3,357
Recurring basis | Level 3
Liabilities:
Series D redeemable convertible preferred stock warrants	814
Change in the fair value of Series D Warrants
Balance at the beginning of the period	126
Change in fair value of warrant liability	688
Balance at the end of the period	$ 814

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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.

+ References

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



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-Publisher FASB

-Name Accounting Standards Codification

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Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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-Publisher FASB

-Name Accounting Standards Codification

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-Section 25

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Fair value portion of warrants not settleable in cash classified as equity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

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