QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details Textuals) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Jan. 31, 2020	Jan. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Deferred Tax Expense from Stock Options Exercised	$ 47.6	$ 16.6
Net income attributable to HEICO	$ 46.3	$ 15.1
Earnings Per Share, Basic	$ 0.34	$ 0.11

Amount of deferred tax expense from write-off of the deferred tax asset related to deductible stock options at exercise.

No definition available.

Name:	us-gaap_DeferredTaxExpenseFromStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration