SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details Textuals) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016	Jul. 31, 2018	Jan. 31, 2018	Apr. 30, 2017
Summary Of Significant Accounting Policies (Details) [Abstract]
Common Stock Dividend Percentage Rate				25.00%	25.00%	25.00%
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
Revenue Recognition [Abstract]
Percent of Revenue from Services Renderred	10.00%
Net Sales Recognized from Percentage-Of-Completion Method	2.00%	3.00%	3.00%
Proceeds from Life Insurance Policy			$ 100
Net Investment Related to Deferred Compensation Plan	$ 11,500	$ 13,400	$ 10,529
Subsidiary Seven [Member] | HEICO Electronic [Member] | Subsidiary Seven [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	53.10%
Subsidiary Six [Member] | HEICO Electronic [Member] | Subsidiary Six [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	85.00%
Subsidiary Four [Member] | HEICO Electronic [Member] | Subsidiary Four [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	95.90%
Subsidiary Three [Member] | HEICO Electronic [Member] | Subsidiary Three [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	82.50%
Joint Venture [Member] | Heico Aerospace [Member] | Joint Venture [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	84.00%
Subsidiary Two [Member] | Heico Flight Support Corp [Member] | Subsidiary Two [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	84.00%
Subsidiary Two [Member] | HEICO Electronic [Member] | Subsidiary Two [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Subsidiary Two [Member] | Heico Aerospace [Member] | Subsidiary Two [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	82.30%
Certain Subsidiaries [Member] | Heico Flight Support Corp [Member] | Subsidiaries [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Heico Aerospace [Member] | Lufthansa Technik AG [Member] | Heico Aerospace [Member] | Heico Aerospace [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage of interest owned by noncontrolling shareholders	20.00%
Subsidiary One [Member] | Heico Flight Support Corp [Member] | Subsidiary One [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.00%
Subsidiary One [Member] | HEICO Electronic [Member] | Subsidiary One [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Subsidiary One [Member] | Heico Aerospace [Member] | Subsidiary One [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	80.10%
Subsidiary Five [Member] | HEICO Electronic [Member] | Subsidiary Five [Member]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Noncontrolling Interest, Ownership Percentage by Parent	78.00%