Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Trade accounts receivable, allowance	$ 47	$ 47
Accumulated depreciation	1,718	1,441
Accumulated amortization	$ 12,166	$ 11,191
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	325,000,000	325,000,000
Common stock, shares issued (in shares)	30,773,748	28,736,436
Common stock, shares outstanding (in shares)	30,420,685	28,383,373
Treasury stock, shares (in shares)	353,063	353,063