Derivative Liabilities - Fair value assumptions, derivative warrant liability (Details) - $ / shares	1 Months Ended	6 Months Ended
	Jul. 31, 2016	Jan. 31, 2017
Notes to Financial Statements
Current exercise price	$ 20.00	$ 15.00
Time to expiration	2 years 1 month	1 year 5 months
Risk-free interest rate	0.76%	1.46%
Estimated volatility	101.00%	167.00%
Dividend		0.00%
Stock price at period end date	$ 10.00	$ 8.00