Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Apr. 30, 2016	Apr. 30, 2015
Income Taxes [Line Items]
Deferred compensation	$ 91,712	$ 73,934
Loss and credit carryforwards	31,023	26,211
Reserves and accruals	14,189	9,344
Deferred rent	7,684	6,432
Deferred revenue	11,464	1,545
Allowance for doubtful accounts	1,431	1,831
Other	5,002	2,609
Gross deferred tax assets	162,505	121,906
Intangibles	(94,284)	(20,828)
Property and equipment	(10,603)	(6,289)
Prepaid expenses	(12,698)	(7,687)
Other	(815)	(5,653)
Gross deferred tax liabilities	(118,400)	(40,457)
Valuation allowances	(22,030)	(21,608)
Net deferred tax asset	$ 22,075	$ 59,841