SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details Textuals) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Jun. 28, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Depreciation Methods	Depreciation and amortization is generally provided on the straight-line method over the estimated useful lives of the various assets.
Business Combination, Description [Abstract]
Business Acquisition, Transaction Costs		$ 3,200
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Assets, Amortization Method	The Company’s intangible assets subject to amortization are amortized on the straight-line method (except for certain customer relationships amortized on an accelerated method) over the following estimated useful lives
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Operating Lease, Right-of-Use Asset	$ 57,103
Operating Lease, Liability	$ 58,294
Defense, Space, and Other [Member]
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Source of Revenue, Percent	59.00%
Aerospace [Member]
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Percent change in Revenue	32.00%
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Operating Lease, Right-of-Use Asset	$ 63,400
Operating Lease, Liability	$ 64,100
HEICO Aerospace [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage of interest owned by noncontrolling shareholders	20.00%		20.00%
Noncontrolling Interest, Ownership Percentage by Parent			80.00%
Lufthansa Technik Ag [Member] | HEICO Aerospace [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage of interest owned by noncontrolling shareholders	20.00%
Heico Flight Support Corp [Member] | Subsidiary One [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	84.00%
Heico Flight Support Corp [Member] | Subsidiary Two [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	85.00%
Heico Flight Support Corp [Member] | Subsidiary Three [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	86.20%
Heico Flight Support Corp [Member] | Subsidiary Four [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	70.00%
Heico Flight Support Corp [Member] | Subsidiary Five [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Flight Support Corp [Member] | Subsidiary Six [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Flight Support Corp [Member] | Subsidiary Seven [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Flight Support Corp [Member] | Subsidiary Eight [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Flight Support Corp [Member] | Subsidiary Nine [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Flight Support Corp [Member] | Subsidiary Ten [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
HEICO Aerospace [Member] | Joint Venture [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	84.00%
HEICO Electronic [Member] | Subsidiary One [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
HEICO Electronic [Member] | Subsidiary Two [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
HEICO Electronic [Member] | Subsidiary Three [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
HEICO Electronic [Member] | Subsidiary Four [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	75.00%
HEICO Electronic [Member] | Subsidiary Five [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	75.00%
HEICO Electronic [Member] | Subsidiary Six [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	82.50%
HEICO Electronic [Member] | Subsidiary Seven [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	85.00%
HEICO Electronic [Member] | Subsidiary Eight [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	90.00%
HEICO Electronic [Member] | Subsidiary Nine [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	92.70%
HEICO Electronic [Member] | Subsidiary Ten [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	95.90%