ACQUISITIONS (Details Textuals) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired									$ 418,265	$ 263,811	$ 166,784
Net sales	$ 421,224	$ 391,500	$ 368,657	$ 343,432	$ 363,299	$ 356,084	$ 350,648	$ 306,227	1,524,813	1,376,258	1,188,648
Net income attributable to HEICO	53,674	$ 45,698	$ 45,686	$ 40,927	44,262	$ 42,002	$ 38,657	$ 31,271	185,985	156,192	$ 133,364
Contingent consideration, liability	$ 27,573				18,881				$ 27,573	18,881
Business Acquisition, Transaction Costs					3,200					$ 3,200
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									12 years	11 years	10 years
Intellectual Property [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									13 years	15 years	12 years
FY 2017 Acquisition [Member]
Business Acquisition [Line Items]
Net sales									$ 49,000
Pro Forma Revenue										$ 1,464,500
AAT [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired									316,632
Cash Acquired from Acquisition									$ 868
CBD [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Carbon by Design
Date on which the acquirer obtains control of the acquiree									Jun. 30, 2017
Description of the acquired entity									CBD is a manufacturer of composite components for UAVs, rockets, spacecraft and other specialized applications.
A2C [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Air Cost Control
Date on which the acquirer obtains control of the acquiree									Apr. 30, 2017
Description of the 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.
Percentage of interest acquired in the subsidiary	80.10%								80.10%
Percentage of interest owned by noncontrolling shareholders	19.90%								19.90%
FY 2015 Acquisition [Member]
Business Acquisition [Line Items]
Net sales									$ 62,900
Pro Forma Revenue									1,244,911
Net income attributable to HEICO									$ 7,900
Astroseal Products Manufacturing Corp [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Astroseal Products Mfg. Corporation
Date on which the acquirer obtains control of the acquiree									Aug. 31, 2015
Description of the acquired entity									Astroseal manufactures expanded foil mesh, which is integrated into composite aerospace structures for lightning strike protection in fixed and rotary wing aircraft.
Midwest Microwave Solutions [Member] | HEICO Electronic [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Midwest Microwave Solutions, Inc.
Date on which the acquirer obtains control of the acquiree									Aug. 31, 2015
Description of the acquired entity									MMS designs, manufactures and sells unique Size, Weight, Power and Cost (SWAP-C) optimized Communications and Electronic Intercept Receivers and Tuners for military and intelligence applications.
Percentage of interest acquired in the subsidiary	80.10%								80.10%
Percentage of interest owned by noncontrolling shareholders	19.90%								19.90%
Aerospace & Commercial Technologies [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Aerospace & Commercial Technologies, LLC
Date on which the acquirer obtains control of the acquiree									Aug. 31, 2015
Description of the acquired entity									ACT is a provider of products and services necessary to maintain up-to-date F-16 fighter aircraft operational capabilities.
Percentage of interest acquired in the subsidiary	80.10%								80.10%
Percentage of interest owned by noncontrolling shareholders	19.90%								19.90%
TEP [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Thermal Energy Products, Inc.
Date on which the acquirer obtains control of the acquiree									May 31, 2015
Description of the acquired entity									TEP engineers, designs and manufactures removable/reusable insulation systems for industrial, commercial, aerospace and defense applications.
Harter [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Harter Aerospace, LLC
Date on which the acquirer obtains control of the acquiree									Jan. 31, 2015
Description of the acquired entity									Harter is a globally recognized component and accessory maintenance, repair, and overhaul (MRO) station specializing in commercial aircraft accessories, including thrust reverse actuation systems and pneumatics, and electromechanical components.
Percentage of interest acquired in the subsidiary	80.10%								80.10%
Percentage of interest owned by noncontrolling shareholders	19.90%								19.90%
Aeroworks [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Aeroworks International Holding B.V.
Date on which the acquirer obtains control of the acquiree									Jan. 31, 2015
Description of the acquired entity									Aeroworks, which is headquartered in the Netherlands and maintains a significant portion of its production facilities in Thailand and Laos, is a manufacturer of both composite and metal parts used primarily in aircraft interior applications, including seating, galleys, lavatories, doors, and overhead bins.
Percentage of interest acquired in the subsidiary	80.00%								80.00%
Percentage of interest owned by noncontrolling shareholders	20.00%								20.00%
Electronic Technologies Group [Member]
Business Acquisition [Line Items]
Net sales									$ 574,261	511,272	$ 390,982
Electronic Technologies Group [Member] | FY 2017 Acquisition [Member]
Business Acquisition [Line Items]
Contingent consideration, liability	$ 13,600								13,600
Amount of contingent purchase consideration, the company could be required to pay	20,000								$ 20,000
Electronic Technologies Group [Member] | AAT [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									AeroAntenna Technology, Inc.
Date on which the acquirer obtains control of the acquiree									Sep. 15, 2017
Net sales										10,200
Pro Forma Revenue									$ 1,582,653	1,428,336
Net income attributable to HEICO										2,500
Description of the acquired entity									AAT designs and produces high performance active antenna systems for commercial aircraft, precision guided munitions, other defense applications and commercial uses.
Amount of contingent purchase consideration, the company could be required to pay	$ 13,800								$ 13,800
Electronic Technologies Group [Member] | AAT [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									15 years
Electronic Technologies Group [Member] | AAT [Member] | Intellectual Property [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									15 years
Electronic Technologies Group [Member] | Robertson [Member]
Business Acquisition [Line Items]
Name of the entity in which interest is owned									Robertson Fuel Systems, LLC
Cash Acquired from Acquisition									$ 3,271
Date on which the acquirer obtains control of the acquiree									Jan. 11, 2016
Net sales										84,100
Pro Forma Revenue											$ 1,275,926
Net income attributable to HEICO										12,300
Description of the acquired entity									Robertson designs and produces mission-extending, crashworthy and ballistically self-sealing auxiliary fuel systems for military rotorcraft.
Business Acquisition, Transaction Costs					$ 3,100					$ 3,100
Electronic Technologies Group [Member] | Robertson [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									15 years
Electronic Technologies Group [Member] | Robertson [Member] | Intellectual Property [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									22 years
Electronic Technologies Group [Member] | Certain Assets [Member]
Business Acquisition [Line Items]
Date on which the acquirer obtains control of the acquiree									Dec. 31, 2015
Description of the acquired entity									designs and manufactures underwater locator beacons used to locate aircraft cockpit voice recorders, flight data recorders, marine ship voyage recorders and other devices which have been submerged under water