Investments - Schedule of Unrealized Loss Breakdown by Investment (Details) - USD ($)	Jul. 31, 2020	Apr. 30, 2020
Less than 12 months, Fair Value	$ 4,258,000	$ 7,742,000
Less than 12 months, Unrealized Loss	(504,000)	(938,000)
12 months or greater, Fair Value	1,718,000	2,159,000
12 months or greater, Unrealized Loss	(198,000)	(375,000)
Total, Fair Value	5,976,000	9,901,000
Total, Unrealized Loss	(702,000)	(1,313,000)
Municipal Bonds [Member]
Less than 12 months, Fair Value	62,000	2,203,000
Less than 12 months, Unrealized Loss		(42,000)
12 months or greater, Fair Value	342,000	484,000
12 months or greater, Unrealized Loss	(38,000)	(47,000)
Total, Fair Value	404,000	2,687,000
Total, Unrealized Loss	(38,000)	(89,000)
REITs [Member]
Less than 12 months, Fair Value	48,000	43,000
Less than 12 months, Unrealized Loss	(26,000)	(30,000)
12 months or greater, Fair Value	28,000	24,000
12 months or greater, Unrealized Loss	(10,000)	(14,000)
Total, Fair Value	76,000	67,000
Total, Unrealized Loss	(36,000)	(44,000)
Equity Securities [Member]
Less than 12 months, Fair Value	4,148,000	5,496,000
Less than 12 months, Unrealized Loss	(478,000)	(866,000)
12 months or greater, Fair Value	1,348,000	1,651,000
12 months or greater, Unrealized Loss	(150,000)	(314,000)
Total, Fair Value	5,496,000	7,147,000
Total, Unrealized Loss	$ (628,000)	$ (1,180,000)