Fair value of financial instruments (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 7,166	$ 0
Issuance of warrants to purchase intangible assets		851
Revaluation of warrant liability		557
Issuance of warrants with the issuance of Preferred Series A Convertible stock		6,731
Issuance of additional warrants due to anti-dilution provision		141
Total (gains) or losses (realized/unrealized) included in consolidated statements of operations	(2,204)	557
Purchases, issuances and settlements	0
Reclassification of derivative liabilities to equity upon modification of terms (Note 6)	(9,370)
Transfers in and/or out of Level III		0
Balance	0	7,166
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	7,166	0
Issuance of warrants to purchase intangible assets		851
Revaluation of warrant liability		557
Issuance of warrants with the issuance of Preferred Series A Convertible stock		6,731
Issuance of additional warrants due to anti-dilution provision		141
Total (gains) or losses (realized/unrealized) included in consolidated statements of operations	2,204
Purchases, issuances and settlements	0
Reclassification of derivative liabilities to equity upon modification of terms (Note 6)	(9,370)
Transfers in and/or out of Level III		0
Balance	$ 0	$ 7,166