Note 16 - Warrant liabilities - Warrant Activity (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Balance (in shares)	774,000
Weighted average remaining contractual life (Year)	1 year 138 days	1 year 229 days
Weighted average exercise price (in dollars per share)	$ 6.60
Exercisable (in shares)	774,000
Exercisable, weighted average remaining contractual life (Year)	1 year 138 days	1 year 229 days
Exercisable, weighted average exercise price (in dollars per share)	$ 6.60
Granted/Vested (in shares)
Forfeited (in shares)
Exercised (in shares)
Balance (in shares)	774,000	774,000
Weighted average exercise price (in dollars per share)	$ 6.60	$ 6.60
Exercisable (in shares)	774,000	774,000
Exercisable, weighted average exercise price (in dollars per share)	$ 6.60	$ 6.60