Note 7 - Results of Operations by Quarter (Unaudited) - Summary of Operations by Quarter (Details) - USD ($)	3 Months Ended									12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016		Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Revenues	$ 10,914,000	$ 10,201,000	$ 10,279,000	$ 9,990,000	$ 9,017,000		$ 10,338,000	$ 11,442,000	$ 10,815,000	$ 41,384,000	$ 41,612,000	$ 43,978,000
Costs and expenses	14,329,000	13,834,000	13,545,000	12,843,000	12,337,000		12,120,000	12,018,000	11,777,000
Loss from operations	(3,415,000)	(3,633,000)	(3,266,000)	(2,853,000)	(3,320,000)		(1,782,000)	(576,000)	(962,000)
Other income, net	1,205,000	817,000	2,005,000	1,072,000	948,000	[1]	1,159,000	728,000	827,000
Income (loss) before taxes	(2,210,000)	(2,816,000)	(1,261,000)	(1,781,000)	(2,372,000)		(623,000)	152,000	(135,000)	(8,068,000)	(2,978,000)	(310,000)
Benefit from income taxes	1,135,000	1,465,000	4,240,000	310,000	1,410,000		285,000	55,000	185,000	7,150,000	1,935,000	1,120,000
Net (loss) income	$ (1,075,000)	$ (1,351,000)	$ 2,979,000	$ (1,471,000)	$ (962,000)		$ (338,000)	$ 207,000	$ 50,000	$ (918,000)	$ (1,043,000)	$ 810,000
Basic and diluted net (loss) income per share (in dollars per share)	$ (0.77)	$ (0.98)	$ 2.16	$ (1.07)	$ (0.70)		$ (0.25)	$ 0.15	$ 0.04	$ (0.66)	$ (0.76)	$ 0.59

[1] Includes other-than-temporary impairment losses on investments of $376,000