Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 20,461	$ 9,758	$ (20,786)
Other comprehensive income (loss), net of tax:
Change in pension benefits, net of deferred taxes of $3,944, $2,905 and $3,624, respectively	6,170	(4,543)	(5,669)
Total Comprehensive Income (Loss)	$ 26,631	$ 5,215	$ (26,455)