Note 8 - Common Stock - Activity of Stock Purchase Warrants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Outstanding, shares (in shares)
Outstanding, weighted average exercise price (in dollars per share)	$ 0.03
Issued (in shares)	57,348,383
Issued (in dollars per share)	$ 0.03
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited or expired (in shares)
Forfeited or expired, weighted average exercise price (in dollars per share)
Outstanding, shares (in shares)	57,348,383