CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interests [Member]	Redeemable Noncontrolling Interests [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Common Stock [Member] Common Class A [Member]	Capital in Excess of Par Value [Member]	Deferred Compensation Obligation [Member]	HEICO Stock Held By Irrevocable Trust [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Noncontrolling Interest [Member]	Noncontrolling Interest [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Total Shareholders Equity [Member]	Total Shareholders Equity [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]
Balances at Oct. 31, 2017				$ 338	$ 507	$ 326,544	$ 3,118	$ (3,118)	$ (10,556)	$ 844,247		$ 87,212		$ 1,248,292
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 254,312								(4,921)	259,233
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	26,047	$ 13,070										12,977
Comprehensive Income (Loss)	280,359													267,289
Cash dividends										(15,363)				(15,363)
Stock Issued During Period, Value, Stock Dividend				191	286
Adjustments to Additional Paid in Capital, Stock Split	477
Dividends, Common Stock, Stock										(28)				(28)
Issuance of Common Stock to HEICO SIP				1	1	7,868								7,870
Share-based Compensation Expense						9,283								9,283
Proceeds from stock option exercises				7	2									4,031
APIC, Share-based Payment Arrangement, Option, Increase for Cost Recognition						4,022
Stock Redeemed or Called During Period, Value				(3)		(24,980)								(24,983)
Noncontrolling interests assumed related to acquisition		(2,491)										(5,350)		(5,350)
Distributions to noncontrolling interests		(12,005)										(1,054)		(1,054)
Adjustments to redemption amount of redeemable noncontrolling interests		(3,627)								3,627				3,627
Deferred Compensation Obligation							810
Stock Held During Period Value Deferred Compensation Obligation								(810)
Adjustments to Additional Paid in Capital, Other						(1,266)
Stockholders' Equity, Other									221	533		272		(1,306)
Balances at Oct. 31, 2018				534	796	320,994	3,928	(3,928)	(15,256)	1,091,183		104,757		1,503,008
Redeemable noncontrolling interests at Oct. 31, 2017		131,123
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	26,047	13,070										12,977
Noncontrolling interests assumed related to acquisition		2,491										5,350		5,350
Distributions to noncontrolling interests		(12,005)										(1,054)		(1,054)
Adjustments to redemption amount of redeemable noncontrolling interests		(3,627)								3,627				3,627
Temporary Equity, Other	994
Redeemable noncontrolling interests at Oct. 31, 2018		132,046
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	326,413								(1,483)	327,896
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	31,620	18,116										13,504
Comprehensive Income (Loss)	358,033													339,917
Cash dividends										(18,691)				(18,691)
Issuance of Common Stock to HEICO SIP						8,666								8,666
Share-based Compensation Expense						10,334								10,334
Proceeds from stock option exercises				12	8									8,547
APIC, Share-based Payment Arrangement, Option, Increase for Cost Recognition						8,527
Stock Redeemed or Called During Period, Value				(5)	(1)	(64,008)								(64,014)
Noncontrolling interests assumed related to acquisition		(38,696)										(2,551)		(2,551)
Distributions to noncontrolling interests		(17,847)										(93,022)		(93,022)
Adjustments to redemption amount of redeemable noncontrolling interests		16,434								(16,434)				(16,434)
Deferred Compensation Obligation							304
Stock Held During Period Value Deferred Compensation Obligation								(304)
Adjustments to Additional Paid in Capital, Other						96
Stockholders' Equity, Other					1							2		99
Balances at Oct. 31, 2019	1,694,660			541	804	284,609	4,232	(4,232)	(16,739)	1,397,327		28,118		1,694,660
Balances (Accounting Standards Update 2014-09 [Member]) at Oct. 31, 2019											$ 13,373		$ 326		$ 13,699
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	31,620	18,116										13,504
Noncontrolling interests assumed related to acquisition		38,696										2,551		2,551
Distributions to noncontrolling interests		(17,847)										(93,022)		(93,022)
Adjustments to redemption amount of redeemable noncontrolling interests		16,434								(16,434)				(16,434)
Redeemable noncontrolling interests at Oct. 31, 2019	188,264	188,264
Redeemable noncontrolling interests (Accounting Standards Update 2014-09 [Member]) at Oct. 31, 2019			$ 819
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	321,574								7,590	313,984
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	22,218	16,932										5,286
Comprehensive Income (Loss)	343,792													326,860
Cash dividends										(21,552)				(21,552)
Issuance of Common Stock to HEICO SIP				1		9,723								9,724
Share-based Compensation Expense						10,134								10,134
Proceeds from stock option exercises					6									6,955
APIC, Share-based Payment Arrangement, Option, Increase for Cost Recognition						6,949
Stock Redeemed or Called During Period, Value					(1)	(12,119)								(12,120)
Noncontrolling interests assumed related to acquisition		(22,204)
Distributions to noncontrolling interests		(16,176)										(1,732)		(1,732)
Acquisitions of noncontrolling interests	7,475
Adjustments to redemption amount of redeemable noncontrolling interests		1,714								(1,714)				(1,714)
Deferred Compensation Obligation							654
Stock Held During Period Value Deferred Compensation Obligation								(654)
Adjustments to Additional Paid in Capital, Other						634
Stockholders' Equity, Other												(1,242)		(608)
Balances at Oct. 31, 2020	2,010,607			$ 542	$ 809	$ 299,930	$ 4,886	$ (4,886)	$ (9,149)	1,688,045		30,430		2,010,607
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	22,218	16,932										5,286
Noncontrolling interests assumed related to acquisition		22,204
Temporary Equity, Stock Issued During Period, Value, New Issues	14,329
Distributions to noncontrolling interests		(16,176)										$ (1,732)		(1,732)
Acquisitions of noncontrolling interests	(7,475)
Adjustments to redemption amount of redeemable noncontrolling interests		1,714								$ (1,714)				$ (1,714)
Temporary Equity, Other	1,416
Redeemable noncontrolling interests at Oct. 31, 2020	$ 221,208	$ 221,208