Goodwill And Intangible Assets (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Goodwill And Intangible Assets [Abstract]
Intangible assets amortization expense	$ 400	$ 600	$ 769	$ 1,123