Investments - Schedule of Investments (Details) - USD ($)	9 Months Ended	12 Months Ended
	Jan. 31, 2019	Apr. 30, 2018
Cost Basis	$ 23,340,000	$ 23,188,000
Gross Unrealized Gains	2,999,000	3,785,000
Gross Unrealized Losses	(569,000)	(627,000)
Fair Value	25,770,000	26,346,000
Municipal Bonds [Member]
Cost Basis	5,487,000	5,984,000
Gross Unrealized Gains	65,000	66,000
Gross Unrealized Losses	(88,000)	(309,000)
Fair Value	5,464,000	5,741,000
Corporate Bonds [Member]
Cost Basis	56,000	129,000
Gross Unrealized Gains	1,000	2,000
Gross Unrealized Losses
Fair Value	57,000	131,000
REITs [Member]
Cost Basis	89,000	110,000
Gross Unrealized Gains		3,000
Gross Unrealized Losses	(2,000)	(7,000)
Fair Value	87,000	106,000
Equity Securities [Member]
Cost Basis	16,532,000	15,930,000
Gross Unrealized Gains	2,933,000	3,714,000
Gross Unrealized Losses	(479,000)	(311,000)
Fair Value	18,986,000	19,333,000
Money Markets and CDs [Member]
Cost Basis	1,176,000	1,035,000
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	$ 1,176,000	$ 1,035,000