Note 7 - Fair Value of Financial Instruments (Detail) - Range of Estimates of Cumulative Default and Loss Severities and Discount Rates (Fair Value, Inputs, Level 3 [Member])	3 Months Ended	6 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Minimum [Member]
Cumulative default	6.04%	6.28%
Loss Severity (Life)	35.50%	36.70%
Discount rate	4.25%	4.50%
Weighted Average [Member]
Cumulative default	17.24%	17.65%
Loss Severity (Life)	47.92%	48.52%
Discount rate	4.51%	5.17%
Maximum [Member]
Cumulative default	24.67%	26.26%
Loss Severity (Life)	60.20%	56.00%
Discount rate	4.76%	5.54%