Carrying value as of the balance sheet date of accrued customer rebates and credits.

No definition available.

Name:	hei_AccruedCustomerRebatesAndCredits
Namespace Prefix:	hei_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total customer rebates and credits expense deducted within net sales.

+ References

No definition available.

+ Details

Name:	hei_AccruedCustomerRebatesAndCreditsExpense
Namespace Prefix:	hei_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Selected Financial Statement Information (Details) [Abstract]

+ References

No definition available.

+ Details

Name:	hei_SelectedFinancialStatementInformationDetailsAbstract
Namespace Prefix:	hei_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=hei_STEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SELECTED FINANCIAL STATEMENT INFORMATION (Details Textuals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017	Oct. 31, 2017
Selected Financial Statement Information (Details) [Abstract]
Accrued customer rebates and credits	$ 15.1		$ 15.1		$ 12.9
Total customer rebates and credits deducted within net sales	$ 2.5	$ 2.7	$ 7.7	$ 8.1
STE [Member]
Business Acquisition [Line Items]
Percentage of Voting Interests Acquired	85.00%		85.00%