Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 5,271	$ 1,950	$ 11,926	$ 2,511
Other comprehensive income, net of tax:
Change in pension benefits, net of deferred tax of $(110) and $(90), and $(220) and $(180), for the three and six months ended October 31, 2013 and 2012, respectively	173	141	345	282
Total Comprehensive Income	$ 5,444	$ 2,091	$ 12,271	$ 2,793