Note 4 - Subordinated Secured Notes Receivable (Details Textual) - USD ($)		3 Months Ended	12 Months Ended
	Sep. 06, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Net, Total		$ 7,400,000
Gain (Loss) on Extinguishment of Note Receivable			$ 448,000
Financing Receivable, Gross			7,716
Paid-in-Kind Interest from Notes Receivable			337,000
Fair Value Adjustment of Note Receivable			(1,834)
Investment Income, Interest			943,000
Original Note [Member]
Gain (Loss) on Extinguishment of Note Receivable			448,000
A&R Note [Member]
Financing Receivable, Net, Total			2,400,000
Financing Receivable, Gross			$ 3,300,000
Notes Receivable, Interest Rate			6.00%
Paid-in-Kind Interest from Notes Receivable			$ 337,000
Notes Receivable, Interest Rate in the Event of Default			12.00%
Proceeds from Interest Received			$ 35,000
Fair Value Adjustment of Note Receivable	$ 1,100,000	2,600,000
Investment Income, Interest		$ 199,000	66,000
New Note [Member]
Financing Receivable, Net, Total			3,500,000
Financing Receivable, Gross	4,400,000		$ 4,400,000
Notes Receivable, Interest Rate			10.00%
Fair Value Adjustment of Note Receivable	$ 945,000
Investment Income, Interest			$ 62,000
Interest Paid, Excluding Capitalized Interest, Operating Activities			141,000
Proceeds from (Repayments of) Debt, Total			$ 60,000