Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	$ 1,054,283	$ 1,019,871
Liabilities, carried at fair value on a recurring basis	29,603	29,570
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	774,202	756,156
Collateralized Mortgage Backed Securities [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	774,202	756,156
Other securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	255,935	237,476
Other securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	23,229	24,158
Other securities [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	279,164	261,634
Interest rate swaps [Member] | Fair Value, Inputs, Level 2 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	917	2,081
Liabilities, carried at fair value on a recurring basis	62
Interest rate swaps [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	917	2,081
Liabilities, carried at fair value on a recurring basis	62
Borrowings [Member] | Fair Value, Inputs, Level 3 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Liabilities, carried at fair value on a recurring basis	29,541	29,570
Borrowings [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Liabilities, carried at fair value on a recurring basis	29,541	29,570
Fair Value, Inputs, Level 2 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	1,031,054	995,713
Liabilities, carried at fair value on a recurring basis	62
Fair Value, Inputs, Level 3 [Member]
Note 10 - Fair Value of Financial Instruments (Details) - Fair Value Measured on a Recurring Basis [Line Items]
Assets, carried at fair value on a recurring basis	23,229	24,158
Liabilities, carried at fair value on a recurring basis	$ 29,541	$ 29,570