Consolidated Statements Of Operations And Comprehensive Income (Loss) (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014
Income Statement [Abstract]
Tax benefit on discontinued operations	$ (1,016)	$ (1,164)	$ (4,814)	$ (3,591)