Investments (Schedule of Cost and Fair Value of Available For Sale Securities) (Details) (USD $)	Apr. 30, 2011		Apr. 30, 2010
Amortized cost	$ 166,305,000		$ 33,322,000
Gross unrealized gains	806,000		498,000
Gross unrealized losses	(194,000)	[1]	(1,872,000)	[1]
Fair value	166,917,000		31,948,000
Available-for-sale investments in a continuous loss position			15,700,000
Available-for-sale investments, gross unrealized losses, continuous loss position			1,900,000
Mortgage-Backed Securities [Member]
Amortized cost	157,970,000		23,026,000
Gross unrealized gains	401,000		39,000
Gross unrealized losses	(194,000)	[1]	(49,000)	[1]
Fair value	158,177,000		23,016,000
Municipal Bonds [Member]
Amortized cost	8,335,000		8,442,000
Gross unrealized gains	405,000		459,000
Fair value	8,740,000		8,901,000
Trust Preferred Security [Member]
Amortized cost			1,854,000
Gross unrealized gains
Gross unrealized losses		[1]	(1,823,000)	[1]
Fair value			$ 31,000

[1] At April 30, 2011, we had no investments that had been in a continuous loss position for more than twelve months. At April 30, 2010, investments with a cost of $15.7 million and gross unrealized losses of $1.9 million had been in a continuous loss position for more than twelve months.