Property And Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2012		Apr. 30, 2011		Apr. 30, 2010
Property And Equipment [Abstract]
Computer equipment and software	$ 75,096		$ 68,761
Leasehold improvements	42,319		37,788
Furniture and fixtures	29,126		28,187
Automobiles	1,870		1,858
Property and equipment, gross	148,411		136,594
Less: accumulated depreciation and amortization	(98,603)		(93,452)
Property and equipment, net	$ 49,808	[1]	$ 43,142	[1]	$ 24,963	[1]

[1] As of the end of the fiscal year.