Series A redeemable convertible preferred stock (Details Textual) - USD ($)		1 Months Ended		6 Months Ended	12 Months Ended
	May. 08, 2015	Apr. 30, 2014	Feb. 28, 2014	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Debt Conversion, Original Debt, Amount	$ 2,100,000
Conversion of Stock, Shares Issued	7,374,852
Series A Preferred Stock
Class of Stock [Line Items]
Temporary Equity, Shares Issued		594,904	1,405,096			1,999,864
Temporary Equity, Par or Stated Value Per Share						$ 1.00
Debt Conversion, Original Debt, Amount						$ 1,999,864
Proceeds from Issuance of Convertible Preferred Stock		$ 594,904	$ 1,405,096
Temporary Equity, Shares Outstanding					3,999,864
Temporary Equity Shares Outstanding Convertible Into Common Stock Number					3,999,864
Preferred Stock, Dividend Rate, Percentage				8.00%
Temporary Equity Liquidation And Redemption Preference Multiple Of Purchase Price				2
Conversion of Stock, Shares Issued				1
Temporary Equity Redemption Request Of Minimum Percentage Of Holders Of Outstanding Preferred Stock Required				70.00%
Temporary Equity Redemption Number Of Installments				3
Debt Conversion, Converted Instrument, Shares Issued				7,374,852	1,500,000