Investment in account receivable (Narrative) (Details)	Apr. 10, 2015 USD ($) $ / shares shares
Investment in account receivable narrative details
Company will receive an investment in an account receivable with installment payments per year for 11 years	$ 117,000
Company will receive an investment in an account receivable total	$ 1,287,000
Shares of Mentor stock exercise of series D warrants | shares	757,059
Shares of Mentor stock exercise of series D warrants per share | $ / shares	$ 1.6
Mentor shares exchanged for all or part of the installment payments	$ 313,820
Company shares exchanged in the transaction, resulting in a discount from the face value of the account receivable	17.87%
Amortized monthly interest in years	11