Revenue and Contract Receivables, net, Summary of Contract Receivables, net (Details) - USD ($) $ in Thousands	Oct. 27, 2018	Jul. 31, 2018
Contracts Receivable [Abstract]
Billed	$ 12,068	$ 12,905
Unbilled	15,973	13,994
Total contract receivables	28,041	26,899
Allowance for doubtful accounts	(1,300)	(1,284)
Contract receivables, net	26,741	25,615
Contractual retainage balance included under billed contract receivable	800	1,400
Contract receivables net, not expected to be collected within one year	$ 400	$ 500

For unclassified balance sheet, amounts due from customers or clients for goods or services that have been delivered or sold in the normal course of business.

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- Definition

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

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Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

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Amount billed to customers under long-term contracts or programs to be collected after the next fiscal year following the latest fiscal year. Excludes amounts due that have been withheld because of retainage provisions in a contract. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount billed to customers under long-term contracts or programs to be collected in the next fiscal year following the latest fiscal year. Excludes amounts due that have been withheld because of retainage provisions in a contract. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount billed to customers under long-term contracts or programs that have been withheld because of retainage provisions in a contract.

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- Definition

Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

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