ACQUISITIONS (Details Textuals) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Business Acquisition [Line Items]
Net sales	$ 476,884	$ 465,825	$ 430,602	$ 404,410	$ 421,224	$ 391,500	$ 368,657	$ 343,432	$ 1,777,721	$ 1,524,813	$ 1,376,258
Net income	67,377	$ 67,086	$ 59,618	$ 65,152	53,674	$ 45,698	$ 45,686	$ 40,927	259,233	185,985	156,192
Acquisition Costs											3,200
Payments to Acquire Businesses, Net of Cash Acquired									59,775	418,265	$ 263,811
Contingent consideration, liability	$ 20,875				$ 27,573				$ 20,875	$ 27,573
Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									7 years	12 years	11 years
Intellectual Property [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									10 years	13 years	15 years
FY 2017 Acquisition [Member]
Business Acquisition [Line Items]
Net sales									$ 49,000
Pro Forma Revenue											$ 1,464,500
CBD [Member] | Heico Flight Support Corp [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.
A2C [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Apr. 30, 2017
Name of Acquired Entity									Air Cost Control
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.
Percentage of interest acquired in the subsidiary	80.10%								80.10%
Electronic Technologies Group [Member]
Business Acquisition [Line Items]
Net sales									$ 701,827	$ 574,261	511,272
Electronic Technologies Group [Member] | FY 2017 Acquisition [Member]
Business Acquisition [Line Items]
Amount of contingent purchase consideration, the company could be required to pay	$ 20,000								20,000
Contingent consideration, liability	13,900								$ 13,900
Electronic Technologies Group [Member] | AAT [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Sep. 15, 2017
Name of Acquired Entity									AeroAntenna Technology, Inc.
Description of 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
Net sales										10,200
Net income										2,500
Payments to Acquire Businesses, Net of Cash Acquired									316,632
Cash Acquired from Acquisition									$ 868
Pro Forma Revenue										1,582,653	1,428,336
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]
Effective Date of Acquisition									Jan. 11, 2016
Name of Acquired Entity									Robertson Fuel Systems, LLC
Description of Acquired Entity									Robertson designs and produces mission-extending, crashworthy and ballistically self-sealing auxiliary fuel systems for military rotorcraft.
Net sales											84,100
Net income											12,300
Acquisition Costs											3,100
Cash Acquired from Acquisition									$ 3,271
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] | SST [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Sep. 30, 2018
Name of Acquired Entity									SST Components, Inc. (“SST”)
Description of Acquired Entity									SST manufactures discrete semiconductor components, tests electronic components, and custom assembles a wide variety of prototype and off the shelf components into desired package styles for military, space and commercial uses.
Percentage of interest acquired in the subsidiary	53.10%								53.10%
Electronic Technologies Group [Member] | ELT [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Apr. 30, 2018
Description of Acquired Entity									The ELT Product Line designs and manufactures Emergency Locator Transmitter Beacons for the commercial aviation and defense markets, that upon activation, transmit a distress signal to alert search and rescue operations of the aircraft's location.
Electronic Technologies Group [Member] | STE [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Feb. 28, 2018
Name of Acquired Entity									Sensor Technology Engineering, Inc. ("Sensor Technology")
Description of Acquired Entity									Sensor Technology designs and manufactures sophisticated nuclear radiation detectors for law enforcement, homeland security and military applications.
Percentage of interest acquired in the subsidiary	85.00%								85.00%
Electronic Technologies Group [Member] | IDC [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Nov. 30, 2017
Name of Acquired Entity									Interface Displays & Controls, Inc. ("IDC")
Description of Acquired Entity									IDC designs and manufactures electronic products for aviation, marine, military fighting vehicles, and embedded computing markets.
Electronic Technologies Group [Member] | Certain Assets [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Dec. 31, 2015
Description of 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
Flight Support Group [Member]
Business Acquisition [Line Items]
Net sales									$ 1,097,937	$ 967,540	$ 875,870
Flight Support Group [Member] | ODE [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition									Aug. 31, 2018
Name of Acquired Entity									Optical Display Engineering ("ODE")
Description of Acquired Entity									ODE is a Federal Aviation Administration ("FAA")-authorized Part 145 Repair Station focusing on the repair of LCD screens and display modules for aviation displays used in civilian and military aircraft. ODE also holds FAA-Parts Manufacturer Approval authority to supply products that it repairs.
A2C [Member] | A2C [Member] | Heico Flight Support Corp [Member]
Business Acquisition [Line Items]
Percentage of interest owned by noncontrolling shareholders	19.90%								19.90%
STE [Member] | Electronic Technologies Group [Member] | STE [Member]
Business Acquisition [Line Items]
Percentage of interest owned by noncontrolling shareholders	15.00%								15.00%