Stockholders' deficit - Warrants Outstanding (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Options
Warrants Granted, shares	2,366,666
Warrants granted, price	$ 0.03
Warrant Exercised, shares	480,000
Warrants
Beginning balance, warrants	19,637,409	6,300,000
Beginning balance, warrants exercise price	$ 0.03	$ 0.03
Warrants Granted, shares		19,337,409
Warrants granted, price		$ 0.03
Warrant Exercised, shares		(6,000,000)
Warrants Exercised, price		$ 0.15
Ending Balance, warrants	22,004,075	19,637,409
Ending Balance, warrants exercise price	$ 0.03	$ 0.03