Schedule of Components of Provision (Benefit) for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Income Tax Disclosure [Abstract]
Federal	$ 200,370	$ 126,846	$ 98,504
State and local	20,941	12,716	1,222
Total current expense	221,311	139,562	99,726
Federal	(37,033)	(13,079)	(7,785)
State and local	(2,146)	(1,192)	(1,055)
Total deferred (benefit)	(39,179)	(14,271)	(8,840)
Total income tax expense	$ 182,132	$ 125,291	$ 90,886