Income taxes - Future Tax Asset (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss carry forward	$ 20,303,013	$ 20,198,844
Net Operating Loss utilized - Discontinued operations	(2,775,870)
Net taxable loss	3,029,615	104,169
Valuation allowance	(20,556,758)	(20,303,013)
Net future tax asset	$ 0	$ 0