NOTE I - FAIR VALUE OF FINANCIAL INSTRUMENTS (Detail) - Fair Value and Unrealized Losses, Aggregated by Investment Type and Length of Time Individual Securities have been Continuious Unrealized Loss Position (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Apr. 30, 2012
Fair Value, Less than 12 months	$ 708	$ 840
Unrealized Losses, Less than 12 months	(95)	(175)
Fair Value, More than 12 months	129
Unrealized Losses, More than 12 months	(1)
Fair Value	837	840
Unrealized Losses	(96)	(175)
Fixed Income Securities [Member]
Fair Value, Less than 12 months		301
Unrealized Losses, Less than 12 months		(6)
Fair Value, More than 12 months
Unrealized Losses, More than 12 months
Fair Value		301
Unrealized Losses		(6)
Equity Securities [Member]
Fair Value, Less than 12 months	708	539
Unrealized Losses, Less than 12 months	(95)	(169)
Fair Value, More than 12 months	129
Unrealized Losses, More than 12 months	(1)
Fair Value	837	539
Unrealized Losses	$ (96)	$ (169)