CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY AND COMPREHENSIVE INCOME - UNAUDITED - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interests [Member]	Common Stock [Member]	Common Stock [Member] Class A Common Stock [Member]	Capital In Excess Of Par Value [Member]	Deferred Compensation Obligation [Member]	HEICO Stock Held By Irrevocable Trust [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Total Shareholders Equity [Member]
Beginning Balance at Oct. 31, 2023			$ 547	$ 835	$ 578,809	$ 6,318	$ (6,318)	$ (40,180)	$ 2,605,984	$ 47,156	$ 3,193,151
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 242,347							4,503	237,844
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	22,680	$ 15,999								6,681
Comprehensive income	265,027										249,028
Cash dividends									(13,831)		(13,831)
Issuance of common stock to Savings and Investment Plan					9,300						9,300
Share-based compensation expense					9,463						9,463
Proceeds from stock option exercises			1	1							4,151
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					4,149
Redemptions of common stock related to stock option exercises					(2,352)						(2,352)
Distributions to noncontrolling interests		(14,967)								(458)	(458)
Adjustments to redemption amount of redeemable noncontrolling interests		4,608							(4,608)		(4,608)
Adjustments to Additional Paid in Capital, Other					(670)
Stockholders' Equity, Other									(368)		(1,038)
Ending Balance at Apr. 30, 2024			548	836	598,699	6,318	(6,318)	(35,677)	2,825,021	53,379	3,442,806
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2023		364,807
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	22,680	15,999								6,681
Distributions to noncontrolling interests		(14,967)								(458)	(458)
Acquisitions of noncontrolling interests, RNCI	(3,165)
Adjustments to redemption amount of redeemable noncontrolling interests		4,608							(4,608)		(4,608)
Temporary Equity, Other Changes	1,087
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2024		368,369
Beginning Balance at Jan. 31, 2024			548	836	585,888	6,318	(6,318)	(25,962)	2,705,128	50,201	3,316,639
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	113,431							(9,715)	123,146
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	11,340	8,003								3,337
Comprehensive income	124,771										116,768
Issuance of common stock to Savings and Investment Plan					6,724						6,724
Share-based compensation expense					4,582						4,582
Proceeds from stock option exercises											1,897
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					1,897
Redemptions of common stock related to stock option exercises					(1,751)						(1,751)
Distributions to noncontrolling interests		(6,500)								(159)	(159)
Increase to APIC from Purchase of Noncontrolling Interests and Net Assets					1,156						1,156
Adjustments to redemption amount of redeemable noncontrolling interests		3,165							(3,165)		(3,165)
Adjustments to Additional Paid in Capital, Other	203
Stockholders' Equity, Other									(88)		115
Ending Balance at Apr. 30, 2024			548	836	598,699	6,318	(6,318)	(35,677)	2,825,021	53,379	3,442,806
Starting Balance, Redeemable Noncontrolling Interests at Jan. 31, 2024		365,865
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	11,340	8,003								3,337
Distributions to noncontrolling interests		(6,500)								(159)	(159)
Acquisitions of noncontrolling interests, RNCI	(2,109)
Adjustments to redemption amount of redeemable noncontrolling interests		3,165							(3,165)		(3,165)
Temporary Equity, Other Changes	(55)
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2024		368,369
Beginning Balance at Oct. 31, 2024	3,697,406		550	838	599,399	7,272	(7,272)	(26,076)	3,062,166	60,529	3,697,406
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	350,413							25,665	324,748
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	27,955	19,460								8,495
Comprehensive income	378,368										358,908
Cash dividends									(15,272)		(15,272)
Issuance of common stock to Savings and Investment Plan					13,062						13,062
Share-based compensation expense					10,671						10,671
Issuance of common stock for an acquisition				1	10,122						10,123
Proceeds from stock option exercises				1							5,786
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					5,785
Redemptions of common stock related to stock option exercises					(1,415)						(1,415)
Distributions to noncontrolling interests		(16,008)								(1,268)	(1,268)
Adjustments to redemption amount of redeemable noncontrolling interests		42,809							(42,809)		(42,809)
Adjustments to Additional Paid in Capital, Other					357
Stockholders' Equity, Other									(242)		115
Ending Balance at Apr. 30, 2025	4,035,307		550	840	637,981	7,272	(7,272)	(411)	3,328,591	67,756	4,035,307
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2024	366,156	366,156
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	27,955	19,460								8,495
Noncontrolling interests assumed related to acquisitions	27,877
Distributions to noncontrolling interests		(16,008)								(1,268)	(1,268)
Acquisitions of noncontrolling interests, RNCI		(4,205)
Adjustments to redemption amount of redeemable noncontrolling interests		42,809							(42,809)		(42,809)
Temporary Equity, Other Changes	382
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2025	436,471	436,471
Beginning Balance at Jan. 31, 2025			550	839	618,622	7,272	(7,272)	(53,586)	3,180,102	64,201	3,810,728
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	209,968							53,175	156,793
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	15,647	11,887								3,760
Comprehensive income	225,615										213,728
Issuance of common stock to Savings and Investment Plan					10,383						10,383
Share-based compensation expense					6,000						6,000
Proceeds from stock option exercises				1							4,189
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					4,188
Redemptions of common stock related to stock option exercises					(1,320)						(1,320)
Distributions to noncontrolling interests		(7,122)								(205)	(205)
Adjustments to redemption amount of redeemable noncontrolling interests		8,223							(8,223)		(8,223)
Adjustments to Additional Paid in Capital, Other					108
Stockholders' Equity, Other									(81)		27
Ending Balance at Apr. 30, 2025	4,035,307		$ 550	$ 840	$ 637,981	$ 7,272	$ (7,272)	$ (411)	3,328,591	67,756	4,035,307
Starting Balance, Redeemable Noncontrolling Interests at Jan. 31, 2025		424,083
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	15,647	11,887								3,760
Noncontrolling Interest Decrease Adjustment From Business Acquisition	(35)
Distributions to noncontrolling interests		(7,122)								$ (205)	(205)
Acquisitions of noncontrolling interests, RNCI		(947)
Adjustments to redemption amount of redeemable noncontrolling interests		8,223							$ (8,223)		$ (8,223)
Temporary Equity, Other Changes	382
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2025	$ 436,471	$ 436,471