Note 5 - Investment Securities Available for Sale - Securities in a Continuous Unrealized Loss Position (Details) - USD ($)	Sep. 30, 2016	Mar. 31, 2016
US Government Agencies Debt Securities [Member]
Less than 12 months, gross unrealized losses	$ 430	$ 6,752
Less than 12 months, fair value	743,756	2,244,157
Total gross unrealized losses	430	6,752
Total fair value	743,756	2,244,157
12 months or longer, gross unrealized losses
12 months or longer, fair value
Municipal Bonds [Member]
Less than 12 months, gross unrealized losses	119,335	140
Less than 12 months, fair value	7,554,780	480,168
Total gross unrealized losses	119,335	140
Total fair value	7,554,780	480,168
Corporate Bond Securities [Member]
Less than 12 months, gross unrealized losses
Less than 12 months, fair value
Total gross unrealized losses	89,766	101,360
Total fair value	1,910,234	1,898,640
12 months or longer, gross unrealized losses	89,766	101,360
12 months or longer, fair value	1,910,234	1,898,640
Collateralized Mortgage Backed Securities [Member]
Less than 12 months, gross unrealized losses	95,670	33,080
Less than 12 months, fair value	25,614,986	4,367,962
Total gross unrealized losses	229,629	300,237
Total fair value	37,166,102	24,641,999
12 months or longer, gross unrealized losses	133,959	267,157
12 months or longer, fair value	11,551,116	20,274,037
Less than 12 months, gross unrealized losses	215,435	39,972
Less than 12 months, fair value	33,913,522	7,092,287
Total gross unrealized losses	439,160	408,489
Total fair value	47,374,872	29,264,964
12 months or longer, gross unrealized losses	223,725	368,517
12 months or longer, fair value	$ 13,461,350	$ 22,172,677