Receivables Receivables, Sale of Receivables (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 31, 2017	Aug. 31, 2017
Receivables [Abstract]
Receivables Securitization Facility, Amount		$ 700,000
Availability under Securitization Facility		618,000
Transfer of Financial Assets Accounted for as Sale, Receivables Sold under Securitization	$ 1,100,000
Deferred purchase price receivable		0
Transfer of Receivables		580,509
Monthly settlements, net		(31,907)
Deferred purchase price receivable		$ 548,602