CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - UNAUDITED - USD ($) $ in Thousands	9 Months Ended
	Jul. 31, 2022	Jul. 31, 2021
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income from consolidated operations	$ 280,450	$ 236,402
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation, Depletion and Amortization	70,526	68,816
Stock or Unit Option Plan Expense	9,815	6,354
Employer contributions to HEICO Savings and Investment Plan	8,884	7,366
Deferred income tax provision (benefit)	7,858	(16,957)
Change in value of contingent consideration	(4,253)	1,305
Increase (Decrease) in Operating Capital [Abstract]
Increase (Decrease) in Receivables	(18,445)	3,537
Change in contract assets	(4,022)	(1,960)
Increase (Decrease) in Inventories	(61,190)	7,729
Increase (Decrease) in Prepaid Expense and Other Assets	(11,701)	(12,442)
Change in trade accounts payable	18,959	4,166
Change in accrued expenses and other current liabilities	12,963	12,538
Increase (Decrease) in Income Taxes Payable	(2,405)	3,202
Change in other long-term liabilities and assets related to HEICO Leadership Compensation Plan	13,735	12,212
Other Noncash Income (Expense)	2,736	1,835
Net cash provided by operating activities	323,910	334,103
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from Long-term Lines of Credit	162,000
Repayments of Long-Term Lines of Credit	(157,000)	(355,000)
Common Stock Issued Repurchased and Retired Related To Stock Option Exercises	(25,826)	(3,687)
Payments of Ordinary Dividends, Common Stock	(24,466)	(23,002)
Payments of Ordinary Dividends, Noncontrolling Interest	(16,766)	(21,853)
Payments to Noncontrolling Interests	(8,735)	(2,336)
Payments of Debt Issuance Costs	(1,010)	(1,468)
Proceeds from Stock Options Exercised	1,870	4,505
Proceeds from Noncontrolling Interests		534
Proceeds from (Payments for) Other Financing Activities	(157)	(916)
Net cash (used in) provided by financing activities	(70,090)	(403,223)
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments to Acquire Businesses, Net of Cash Acquired	(175,298)	(29,603)
Payments to Acquire Property, Plant, and Equipment	(24,357)	(30,124)
Net Investment Related to Deferred Compensation Plan	(13,400)	(12,400)
Payments for (Proceeds from) Other Investing Activities	(10,296)	3,237
Net cash used in investing activities	(223,351)	(68,890)
Effect of exchange rate changes on cash	(5,162)	974
Net (decrease) increase in cash and cash equivalents	25,307	(137,036)
Cash and cash equivalents at beginning of year	108,298	406,852
Cash and cash equivalents at end of period	$ 133,605	$ 269,816