SELECTED FINANCIAL STATEMENT INFORMATION (Costs and Estimated Earnings on Uncompleted POC Contracts) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
Apr. 30, 2015	Oct. 31, 2014
Costs incurred on uncompleted contracts	$ 16,866us-gaap_ContractRevenueCost	$ 24,437us-gaap_ContractRevenueCost
Estimated Earnings	8,510hei_EstimatedEarnings	11,747hei_EstimatedEarnings
Estimated Revenue on Completed Percentage-of-Completion Contracts	25,376	36,184
Billings to date	(22,769)us-gaap_ContractsRevenue	(29,829)us-gaap_ContractsRevenue
Receivables, Long-term Contracts or Programs	2,607	6,355
Included in the accompanying Condensed Consolidated Balance Sheets under the following captions:
Accounts receivable, net (costs and estimated earnings in excess of billings)	5,052	8,161
Accrued expenses and other current liabilities (billings in excess of costs and estimated earnings)	(2,445)us-gaap_BillingsInExcessOfCostCurrent	(1,806)us-gaap_BillingsInExcessOfCostCurrent
Receivables, Long-term Contracts or Programs	$ 2,607	$ 6,355

Estimated earnings on uncompleted percentage of completion contracts.

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Total estimated revenue, including billed and unbilled, from completed percentage of completion contracts.

+ References

No definition available.

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Liability attributable to (i) billings in excess of costs under the percentage of completion contract accounting method representing the difference between contractually invoiced amounts (billings) and revenue recognized based, for example, on costs incurred to estimated total costs at period end or (ii) contractually invoiced amounts (billings) in excess of costs incurred and accumulated under the completed contract accounting method that are expected to be realized within one year or one operating cycle, whichever is longer, from the reporting date.

+ References

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Costs incurred and are directly related to generating contract revenues.

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Revenue earned during the period arising from products sold or services provided under the terms of a contract, not elsewhere specified in the taxonomy. May include government contracts, construction contracts, and any other contract related to a particular project or product.

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Amount of receivable reflecting the cost incurred on uncompleted contracts in excess of related billings which is expected to be collected within one year or the normal operating cycle, if longer.

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Amount to be collected within one year of the balance sheet date (or one operating cycle, if longer) from customers in accordance with the contractual provisions of long-term contracts or programs including amounts billed and unbilled as of the balance sheet date.

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