Segment Information - Net Income Reconciliation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total profit from reportable segments	$ 60,204	$ 53,906	$ 167,269	$ 161,407
Unallocated amounts:
Administrative costs	(29,420)	(24,787)	(82,794)	(79,347)
Restructuring charges	0	(4,834)	0	(13,991)
Investment and other income	721	434	(1,030)	968
Interest expense	(1,838)	(2,503)	(6,119)	(8,394)
Earnings from continuing operations before income taxes	$ 29,667	$ 22,216	$ 77,326	$ 60,643