Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Allowance	$ 59	$ 122
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	140,000,000	30,000,000
Common stock, shares issued (in shares)	32,859,292	6,384,877
Common stock, shares outstanding (in shares)	32,859,292	6,384,877
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	35,000,000	0
Common stock, shares issued (in shares)	15,486,560	0
Common stock, shares outstanding (in shares)	15,486,560	0