With respect to a business combination completed during the period, this element provides a description of the business, other than the name, which may include the industry, size, products and other important information.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 6
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-SubTopic 10
-Section 50
-Paragraph 2
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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

Name of the acquired entity.

+ References

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Balance Type:	na
Period Type:	duration

- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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-Paragraph 2
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

Name:	dei_LegalEntityAxis=hei_HeicoFlightSupportCorpMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Period Type:

ACQUISITIONS (Details Textuals) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
ACQUISITIONS (Details Textuals) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Business Acquisition [Line Items]
Revenue, Net	$ 391,500	$ 356,084	$ 1,103,589	$ 1,012,959
Pro Forma Revenue	378,600		1,076,800
FY 2017 Acquisition [Member]
Business Acquisition [Line Items]
Revenue, Net	$ 23,100		$ 24,600
Heico Flight Support Corp [Member] \| A2C [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition			Apr. 24, 2017
Name of Acquired Entity			Air Cost Control
Percentage of Voting Interests Acquired	80.10%		80.10%
Description of Acquired Entity			A2C is a leading aviation electrical interconnect product distributor of items such as connectors, wire, cable, protection and fastening systems, in addition to distributing a wide range of electromechanical parts.
Ownership Percentage by Noncontrolling Owners	19.90%		19.90%
Heico Flight Support Corp [Member] \| CBD [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition			Jun. 30, 2017
Name of Acquired Entity			Carbon by Design
Description of Acquired Entity			CBD is a manufacturer of composite components for UAVs, rockets, spacecraft and other specialized applications.