Subsequent events Lease agreement (Details)			1 Months Ended
	Apr. 04, 2016 USD ($) ft²	Jun. 11, 2015 USD ($) ft²	Nov. 30, 2015 USD ($) ft²
Subsequent Event [Line Items]
Area of Land | ft²		22,600	2,300
Operating Lease Monthly Rent | $		$ 60,000	$ 3,100
Subsequent Event [Member]
Subsequent Event [Line Items]
Area of Land | ft²	3,500
Operating Lease Monthly Rent | $	$ 8,300