Contingent Liabilities, Commitments and Legal Matters - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
Jan. 31, 2018	Jul. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Standby repurchase obligations amount	$ 3,076,327	$ 2,200,544
Term of commitments	Up to eighteen months
Repurchase and guarantee reserve balances	$ 8,550	$ 6,345

Terms of commitments under repurchase agreements for the repurchase of products sold to dealers.

No definition available.

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Data Type:	us-types:durationStringItemType
Balance Type:	na
Period Type:	duration