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, 2019			$ 541	$ 804	$ 284,609	$ 4,232	$ (4,232)	$ (16,739)	$ 1,397,327	$ 28,118	$ 1,694,660
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 190,276							(7,065)	197,341
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	13,075	$ 9,422								3,653
Comprehensive income	203,351										193,929
Cash dividends									(10,762)		(10,762)
Issuance of common stock to Savings and Investment Plan					7,281						7,281
Share-based compensation expense					5,275						5,275
Proceeds from stock option exercises				2							2,392
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					2,390
Stock Redeemed or Called During Period, Value					(2,567)						(2,567)
Distributions to noncontrolling interests		(8,977)								(765)	(765)
Adjustments to redemption amount of redeemable noncontrolling interests		260							(260)		(260)
Adjustments to Additional Paid in Capital, Other					336
Stockholders' Equity, Other			1								337
Ending Balance at Apr. 30, 2020			542	806	297,324	4,232	(4,232)	(23,804)	1,583,646	31,006	1,889,520
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2019		188,264
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	13,075	9,422								3,653
Noncontrolling Interest, Increase from Business Combination	7,538
Distributions to noncontrolling interests		(8,977)								(765)	(765)
Adjustments to redemption amount of redeemable noncontrolling interests		260							(260)		(260)
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2020		196,507
Beginning Balance at Jan. 31, 2020			541	805	287,779	4,232	(4,232)	(19,263)	1,508,784	30,601	1,809,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	70,912							(4,541)	75,453
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,291	4,655								636
Comprehensive income	76,203										71,548
Issuance of common stock to Savings and Investment Plan					5,983						5,983
Share-based compensation expense					2,629						2,629
Proceeds from stock option exercises				1							864
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					863
Stock Redeemed or Called During Period, Value					(5)						(5)
Distributions to noncontrolling interests		(4,630)								(231)	(231)
Adjustments to redemption amount of redeemable noncontrolling interests		591							(591)		(591)
Adjustments to Additional Paid in Capital, Other					75
Stockholders' Equity, Other			1								76
Ending Balance at Apr. 30, 2020			542	806	297,324	4,232	(4,232)	(23,804)	1,583,646	31,006	1,889,520
Starting Balance, Redeemable Noncontrolling Interests at Jan. 31, 2020		195,893
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,291	4,655								636
Noncontrolling Interest, Increase from Business Combination		(2)
Distributions to noncontrolling interests		(4,630)								(231)	(231)
Adjustments to redemption amount of redeemable noncontrolling interests		591							(591)		(591)
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2020		196,507
Beginning Balance 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 Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	152,092							10,823	141,269
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	11,804	9,061								2,743
Comprehensive income	163,896										154,835
Cash dividends									(10,818)		(10,818)
Issuance of common stock to Savings and Investment Plan					7,440						7,440
Share-based compensation expense					4,271						4,271
Proceeds from stock option exercises				2							3,838
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					3,836
Stock Redeemed or Called During Period, Value					(3,624)						(3,624)
Distributions to noncontrolling interests		(12,720)								(1,103)	(1,103)
Adjustments to redemption amount of redeemable noncontrolling interests		5,698							(5,698)		(5,698)
Value of Stock Reversed During Period Deferred Compensation Obligation	109
Value of Stock Issued or Reversed During Period for Deferred Compensation Obligation	(109)
Adjustments to Additional Paid in Capital, Other					142
Stockholders' Equity, Other											142
Ending Balance at Apr. 30, 2021	2,159,890		542	811	311,995	4,777	(4,777)	1,674	1,812,798	32,070	2,159,890
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2020	221,208	221,208
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	11,804	9,061								2,743
Distributions to noncontrolling interests		(12,720)								(1,103)	(1,103)
Adjustments to redemption amount of redeemable noncontrolling interests		5,698							(5,698)		(5,698)
Temporary Equity, Other Changes	19
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2021	223,266	223,266
Beginning Balance at Jan. 31, 2021			542	811	301,107	4,777	(4,777)	2,129	1,744,247	31,323	2,080,159
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	70,218							(455)	70,673
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,748	4,264								1,484
Comprehensive income	75,966										71,702
Issuance of common stock to Savings and Investment Plan					7,440						7,440
Share-based compensation expense					2,042						2,042
Proceeds from stock option exercises											1,388
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					1,388
Stock Redeemed or Called During Period, Value					(53)						(53)
Distributions to noncontrolling interests		(5,342)								(737)	(737)
Adjustments to redemption amount of redeemable noncontrolling interests		2,122							(2,122)		(2,122)
Adjustments to Additional Paid in Capital, Other					71
Stockholders' Equity, Other											71
Ending Balance at Apr. 30, 2021	2,159,890		$ 542	$ 811	$ 311,995	$ 4,777	$ (4,777)	$ 1,674	1,812,798	32,070	2,159,890
Starting Balance, Redeemable Noncontrolling Interests at Jan. 31, 2021		222,225
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,748	4,264								1,484
Distributions to noncontrolling interests		(5,342)								$ (737)	(737)
Adjustments to redemption amount of redeemable noncontrolling interests		2,122							$ (2,122)		$ (2,122)
Temporary Equity, Other Changes	(3)
Ending Balance, Redeemable Noncontrolling Interests at Apr. 30, 2021	$ 223,266	$ 223,266