Note 4 - Fair Value by Major Security Type (Details) - USD ($)	Jun. 30, 2016	Sep. 30, 2015
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Cost Basis		$ 301,193
Unrealized Gains (Losses)
Fair Value	628,206	301,193
Cash Equivalents	628,206	301,193
Short-term marketable securities
Long-term marketable securities
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Certificates of Deposit [Member]
Cost Basis	3,047,164	3,296,238
Unrealized Gains (Losses)
Fair Value	3,047,164	3,296,238
Short-term marketable securities	999,289	249,072
Long-term marketable securities	2,047,875	3,047,166
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Cost Basis	436,012	654,205
Unrealized Gains (Losses)	88	293
Fair Value	436,100	654,498
Cash Equivalents	55,112	160,058
Short-term marketable securities	380,988	494,440
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Corporate Debt Securities [Member]
Cost Basis	952,827	509,029
Unrealized Gains (Losses)	(137)	(594)
Fair Value	952,690	508,435
Short-term marketable securities	952,690	508,435
Long-term marketable securities
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Cost Basis	4,436,003	4,459,472
Unrealized Gains (Losses)	(49)	(301)
Fair Value	4,435,954	4,459,171
Cash Equivalents	55,112	160,058
Short-term marketable securities	2,332,967	1,251,947
Long-term marketable securities	2,047,875	3,047,166
Fair Value, Measurements, Nonrecurring [Member]
Cost Basis	4,436,003	4,760,665
Unrealized Gains (Losses)	(49)	(301)
Fair Value	5,064,160	4,760,364
Cash Equivalents	683,318	461,251
Short-term marketable securities	2,332,967	1,251,947
Long-term marketable securities	2,047,875	3,047,166
Short-term marketable securities	2,332,967	1,251,947
Long-term marketable securities	$ 2,047,875	$ 3,047,166