Note 2 - Summary of Significant Accounting Policies - Investment in Financial Instruments (Details) - USD ($)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Common Stock [Member]
Available-for-sale Securities	$ 158,462,000	$ 158,705,000
Marketable Securities	53,436,000	49,604,000
Available-for-sale Securities, Gross Unrealized Gain (Loss)	105,026,000	109,101,000
Fixed Income Securities [Member]
Available-for-sale Securities	8,172,000	7,336,000
Marketable Securities	4,942,000	4,939,000
Available-for-sale Securities, Gross Unrealized Gain (Loss)	3,230,000	2,397,000
Available-for-sale Securities	166,634,000	166,041,000
Marketable Securities	58,378,000	54,543,000
Available-for-sale Securities, Gross Unrealized Gain (Loss)	$ 108,256,000	$ 111,498,000