Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Recurring [Member] - USD ($) $ in Thousands		Apr. 30, 2019	Apr. 30, 2018
Assets:
Foreign currency forward contracts	[1]	$ 4,824	$ 3,213
Total assets at fair value		4,824	3,213
Liabilities:
Deferred compensation plans	[2]	12,574	11,796
Foreign currency forward contracts	[1]	4,742	5,494
Total liabilities at fair value		17,316	17,290
Level 2 [Member]
Assets:
Foreign currency forward contracts	[1]	4,824	3,213
Total assets at fair value		4,824	3,213
Liabilities:
Deferred compensation plans	[2]	12,574	11,796
Foreign currency forward contracts	[1]	4,742	5,494
Total liabilities at fair value		$ 17,316	$ 17,290

[1] We enter into foreign currency forward contracts to reduce the risk of foreign currency exposures resulting from receivables, payables, intercompany receivables, intercompany payables and loans denominated in foreign currencies. Foreign exchange contracts are valued using market exchange rates. These foreign exchange contracts are not designated as hedges.

[2] Executive officers and other highly compensated employees may defer up to 100 percent of their salary and annual cash incentive compensation and for executive officers, up to 90 percent of their long-term incentive compensation, into various non-qualified deferred compensation plans. Deferrals can be allocated to various market performance measurement funds. Changes in the value of compensation deferred under these plans are recognized each period based on the fair value of the underlying measurement funds.