Note 14 - Financial Derivatives (Detail) (USD $)	3 Months Ended			3 Months Ended	12 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Mar. 31, 2012 Negative Fair Value Member	Dec. 31, 2010 Negative Fair Value Member	Dec. 31, 2011 Negative Fair Value Member	Sep. 30, 2011 Positive Fair Value Member	Dec. 31, 2011 Positive Fair Value Member	Mar. 31, 2012 Positive Fair Value Member
Number Of Swap Agreements	5		5
Interest Rate Swaps Notional Amount	$ 300,000,000		$ 300,000,000
Period Of Interest Rate Swap Agreements	3		3
Pay Weighted Average Fixed Rate	1.95%
Receive Weighted Average Variable Rate	0.48%
Net Accrued On Interest Rate Swaps	1,100,000	1,200,000
Interest Rate Derivative Liabilities, at Fair Value	1,800,000		2,600,000
Notional Amount Of Option Contract				5,500,000				4,300,000
Open Option Contracts Written, at Fair Value				23,000				29,000
Sum of Spot and Forward Contract Notional Amount				171,400,000		128,200,000		238,600,000	159,200,000
Increase Decrease in Fair Value				$ 1,400,000	$ 486,000,000,000		$ 1,700,000	$ 2,200,000