Note I - Capital Stock (Details Textual) - USD ($)	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Issued, Total	0	0
Subsidiaries [Member]
Preferred Stock, Par or Stated Value Per Share	$ 1
Preferred Stock, Shares Issued, Total	500,000
Preferred Stock, Dividend Rate, Percentage	8.00%
Preferred Stock Right of Shareholder, Amount of Shares	400,000
Preferred Stock, Right to Shareholder Value of Redeemed Stock	$ 400,000