Note 3 - Income Taxes - Summary of the Difference Between Statutory Federal Income Tax Rate and Effective Rate (Details)	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Statutory federal income tax rate	34.00%	34.00%	34.00%
State franchise taxes (net of federal tax benefit)	5.20%	(23.30%)	(38.30%)
State enterprise zone benefits		134.90%
Business meals/gifts	(2.30%)	(18.80%)	36.10%
Domestic production activity deduction		(2.20%)	(135.70%)
Dividends received deduction	24.50%	225.70%	(424.60%)
Penalties for uncertain and unrecognized tax benefits			115.50%
Prior year true-up	(2.00%)	(7.30%)	84.70%
Foreign tax credits	4.00%	28.40%	(17.90%)
Effect of state rate change on beginning balance of deferred tax liabilities	1.40%	(5.00%)
Others	0.20%	(5.50%)	(1.30%)
Effective tax rate	65.00%	360.90%	(347.50%)