Segment Information - Net Income Reconciliation (Detail) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2015	Oct. 31, 2014
Segment Reconciliation [Abstract]
Total profit from reportable segments	$ 56,668	$ 59,006
Unallocated amounts:
Administrative costs	(26,566)	(27,755)
Restructuring charges	0	(4,278)
Investment and other income	(759)	323
Interest expense	(2,151)	(2,891)
Earnings from continuing operations before income taxes	$ 27,192	$ 24,405