Segment Information - Net Income Reconciliation (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2014	Oct. 31, 2013
Disclosure Segment Information Net Income Reconciliation [Abstract]
Total profit from reportable segments	$ 59,006	$ 69,341
Unallocated amounts:
Administrative costs	(27,755)	(32,814)
Restructuring charges	(4,278)	(6,840)
Investment and other income	323	762
Interest expense	(2,891)	(3,720)
Earnings from continuing operations before income taxes	24,405	26,729
Income Tax Expense (Benefit), Continuing Operations	(8,906)	(8,595)
Earnings from continuing operations	15,499	18,134
(Loss) earnings from discontinued operations, net of income tax	(1,915)	5,794
Net earnings	$ 13,584	$ 23,928