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	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Income Taxes [Line Items]
Domestic	$ 65,885	$ 42,411	$ 15,915
Foreign	53,817	56,603	31,905
Income before provision for income taxes and equity in earnings of unconsolidated subsidiaries	$ 119,702	$ 99,014	$ 47,820