Consolidated Balance Sheets (Parentheticals) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, Series B convertible redeemable preferred stock liquidation value, share of common stock	1	1
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, shares designated	825,000	825,000
Preferred stock, shares issued	10,000	10,000
Preferred stock, shares outstanding	10,000	10,000
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	10,412,750	9,865,735
Common stock, shares, outstanding	10,412,750	9,865,735
Treasury stock (shares)	11,080	11,080