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, 2016			$ 270	$ 403	$ 306,328	$ 2,460	$ (2,460)	$ (25,326)	$ 681,704	$ 84,326	$ 1,047,705
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 39,706							(1,221)	40,927
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,042	$ 2,294								2,748
Comprehensive income	44,748										42,454
Cash dividends									(6,059)		(6,059)
Issuance of common stock to Savings and Investment Plan					893						893
Share-based compensation expense					1,451						1,451
Proceeds from stock option exercises				1							1,230
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					1,229
Distributions to noncontrolling interests		(1,712)								(274)	(274)
Adjustments to redemption amount of redeemable noncontrolling interests		(1,192)							1,192		1,192
Deferred compensation obligation						(140)
Stock Issued During Period Value Deferred Compensation Obligation							140
Ending Balance at Jan. 31, 2017			270	404	309,901	2,320	(2,320)	(26,547)	717,764	86,800	1,088,592
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2016		99,512
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	5,042	2,294								2,748
Distributions to noncontrolling interests		(1,712)								(274)	(274)
Adjustments to redemption amount of redeemable noncontrolling interests		(1,192)							1,192		1,192
Ending Balance, Redeemable Noncontrolling Interests at Jan. 31, 2017		98,902
Starting Balance at Oct. 31, 2017	1,248,292		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	80,125							14,973	65,152
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	7,537	3,952								3,585
Comprehensive income	87,662										83,710
Cash dividends									(7,395)		(7,395)
Stock Issued During Period, Value, Stock Dividend			84	127
Adjustments to Additional Paid in Capital, Stock Split					(211)
Issuance of common stock to Savings and Investment Plan					980						980
Share-based compensation expense					2,165						2,165
Proceeds from stock option exercises				1							1,425
Proceeds from stock option exercises, Adjustment to Additional Paid in Capital					1,424
Distributions to noncontrolling interests		(1,688)								(194)	(194)
Adjustments to redemption amount of redeemable noncontrolling interests		(2,026)							2,026		2,026
Other										(1)	995
Adjustments to Additional Paid in Capital, Other	(994)
Ending Balance at Jan. 31, 2018	1,330,014		$ 422	$ 635	$ 329,908	$ 3,118	$ (3,118)	$ 4,417	904,030	90,602	1,330,014
Starting Balance, Redeemable Noncontrolling Interests at Oct. 31, 2017	131,123	131,123
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	7,537	3,952								3,585
Distributions to noncontrolling interests		(1,688)								$ (194)	(194)
Adjustments to redemption amount of redeemable noncontrolling interests		(2,026)							$ 2,026		$ 2,026
Temporary Equity, Other Changes	994
Ending Balance, Redeemable Noncontrolling Interests at Jan. 31, 2018	$ 132,355	$ 132,355