Amount of amortization expense attributable to debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Date the credit facility terminates, in CCYY-MM-DD format.

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Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Date the credit facility first became available, in CCYY-MM-DD format.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Long - Term Debt - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018	Jul. 31, 2018
Line of Credit Facility [Line Items]
Fees to secure the facility, amortized amount			$ 785,000	$ 785,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, maturity period			5 years
Line of credit, commencement date			Jun. 30, 2016
Line of credit, maturity date			Feb. 01, 2019
Line of credit, outstanding amount	$ 0		$ 0		$ 0
Line of credit, borrowing availability	406,327,000		406,327,000
Fees to secure the facility, amortized amount	392,000	$ 392,000	785,000	$ 785,000
Revolving Credit Facility [Member] \| Other Noncurrent Assets [Member]
Line of Credit Facility [Line Items]
Fees to secure the facility, unamortized amount	$ 3,794,000		$ 3,794,000		$ 4,579,000