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]
Starting Balance at Oct. 31, 2019			$ 541	$ 804	$ 284,609	$ 4,232	$ (4,232)	$ (16,739)	$ 1,397,327	$ 28,118	$ 1,694,660
Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 119,364							(2,524)	121,888
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	7,784	$ 4,767								3,017
Comprehensive income	127,148										122,381
Cash dividends									(10,762)		(10,762)
Issuance of common stock to Savings and Investment Plan					1,298						1,298
Share-based compensation expense					2,646						2,646
Proceeds from stock option exercises				1							1,528
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					1,527
Stock Redeemed or Called During Period, Value					(2,562)						(2,562)
Distributions to noncontrolling interests		(4,347)								(534)	(534)
Adjustments to redemption amount of redeemable noncontrolling interests		(331)							331		331
Adjustments to Additional Paid in Capital, Other					261						261
Ending Balance at Jan. 31, 2020			541	805	287,779	4,232	(4,232)	(19,263)	1,508,784	30,601	1,809,247
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2019		188,264
Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	7,784	4,767								3,017
Noncontrolling Interest, Increase from Business Combination		7,540
Distributions to noncontrolling interests		(4,347)								(534)	(534)
Adjustments to redemption amount of redeemable noncontrolling interests		(331)							331		331
Ending Balance, Redeemable Noncontrolling Interests at Jan. 31, 2020		195,893
Starting 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
Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	81,874							11,278	70,596
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	6,056	4,797								1,259
Comprehensive income	87,930										83,133
Cash dividends									(10,818)		(10,818)
Share-based compensation expense					2,229						2,229
Proceeds from stock option exercises				2							2,450
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					2,448
Stock Redeemed or Called During Period, Value					(3,571)						(3,571)
Distributions to noncontrolling interests		(7,378)								(366)	(366)
Adjustments to redemption amount of redeemable noncontrolling interests		3,576							(3,576)		(3,576)
Value of Stock Issued or Reversed During Period for Deferred Compensation Obligation						(109)
Value of Stock Reversed During Period Deferred Compensation Obligation							109
Adjustments to Additional Paid in Capital, Other					71						71
Ending Balance at Jan. 31, 2021	2,080,159		$ 542	$ 811	$ 301,107	$ 4,777	$ (4,777)	$ 2,129	1,744,247	31,323	2,080,159
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2020	221,208	221,208
Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	6,056	4,797								1,259
Distributions to noncontrolling interests		(7,378)								$ (366)	(366)
Adjustments to redemption amount of redeemable noncontrolling interests		3,576							$ (3,576)		$ (3,576)
Temporary Equity, Other Changes	22
Ending Balance, Redeemable Noncontrolling Interests at Jan. 31, 2021	$ 222,225	$ 222,225