Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment securities available for sale	$ 1,577	$ 1,497
Maximum [Member]
Investments, Debt and Equity Securities [Abstract]
Unrealized investment losses or gains	$ 100	$ 100	$ 100

Amount before tax of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant