Domestic and Foreign Components of Income (Loss) From Continuing Operations Before Domestic and Foreign Income and Other Taxes And Equity in Earnings of Unconsolidated Subsidiaries (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Income Taxes [Line Items]
Domestic	$ 42,411	$ 15,915	$ 42,375
Foreign	56,603	31,905	38,429
Income before provision for income taxes and equity in earnings of unconsolidated subsidiaries	$ 99,014	$ 47,820	$ 80,804