Note 12 - Retirement Plans (Details) - Weighted-Average Asset Allocation by Asset Category	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash [Member]
Note 12 - Retirement Plans (Details) - Weighted-Average Asset Allocation by Asset Category [Line Items]
Low Target Range	0.00%
High Target Range	20.00%
Actual plan asset allocations	2.00%	2.00%
Debt Securities [Member]
Note 12 - Retirement Plans (Details) - Weighted-Average Asset Allocation by Asset Category [Line Items]
Low Target Range	10.00%
High Target Range	70.00%
Actual plan asset allocations	63.00%	63.00%
Equity Securities [Member]
Note 12 - Retirement Plans (Details) - Weighted-Average Asset Allocation by Asset Category [Line Items]
Low Target Range	30.00%
High Target Range	90.00%
Actual plan asset allocations	35.00%	35.00%
Total [Member]
Note 12 - Retirement Plans (Details) - Weighted-Average Asset Allocation by Asset Category [Line Items]
Actual plan asset allocations	100.00%	100.00%