Condensed Consolidated Statement of Stockholders' Equity (Unaudited) (Parentheticals)	Jun. 30, 2018 $ / shares
Cumulative Preferred Stock [Member]
Preferred stock, dividend rate	6.00%
Preferred stock, par value (in dollars per share)	$ 0.25
Cumulative Convertible Preferred Stock [Member]
Preferred stock, dividend rate	10.00%
Preferred stock, par value (in dollars per share)	$ 0.25
Participating Convertible Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	0.25
Series 2003 Convertible Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	0.25
Common Class A [Member]
Common Stock, Par Value (in dollars per share)	0.25
Common Class B [Member]
Common Stock, Par Value (in dollars per share)	0.25
Common Stock, Par Value (in dollars per share)	$ 0.25