CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Redeemable Noncontrolling Interests [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]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Total Shareholders Equity [Member]
Balances at Oct. 31, 2014			$ 268	$ 397	$ 269,351	$ 1,138	$ (1,138)	$ (8,289)	$ 437,757	$ 75,135	$ 774,619
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 116,573							(16,791)	133,364
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	19,340	$ 6,534								12,806
Comprehensive Income (Loss)	135,913										129,379
Cash dividends									(9,343)		(9,343)
Issuance of common stock to HEICO Savings and Investment Plan			1	1	5,752						5,754
Share-based compensation expense					6,048						6,048
Proceeds from stock option exercises				2	3,671						3,673
Tax benefit from stock option exercises					1,402						1,402
Distributions to noncontrolling interests		(5,166)								(4,533)	(4,533)
Adjustments to redemption amount of redeemable noncontrolling interests		13,724							(13,724)		(13,724)
Deferred Compensation Obligation						645
Stock Held During Period Value Deferred Compensation Obligation							(645)
Adjustments to Additional Paid in Capital, Other					(4)
Stockholders' Equity, Other											(4)
Balances at Oct. 31, 2015			269	400	286,220	1,783	(1,783)	(25,080)	548,054	83,408	893,271
Redeemable noncontrolling interests at Oct. 31, 2014		39,966
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	19,340	6,534								12,806
Distributions to noncontrolling interests		(5,166)								(4,533)	(4,533)
Adjustments to redemption amount of redeemable noncontrolling interests		13,724							(13,724)		(13,724)
Noncontrolling interests assumed related to acquisition		36,224
Redeemable noncontrolling interests at Oct. 31, 2015		91,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	155,946							(246)	156,192
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	19,896	9,968								9,928
Comprehensive Income (Loss)	175,842										165,874
Cash dividends									(10,724)		(10,724)
Issuance of common stock to HEICO Savings and Investment Plan			1	1	6,890						6,892
Share-based compensation expense					6,434						6,434
Proceeds from stock option exercises				2	5,922						5,924
Tax benefit from stock option exercises					868						868
Distributions to noncontrolling interests		(9,957)								(9,060)	(9,060)
Adjustments to redemption amount of redeemable noncontrolling interests		11,818							(11,818)		(11,818)
Deferred Compensation Obligation						677
Stock Held During Period Value Deferred Compensation Obligation							(677)
Adjustments to Additional Paid in Capital, Other					(6)
Stockholders' Equity, Other										50	44
Balances at Oct. 31, 2016	1,047,705		270	403	306,328	2,460	(2,460)	(25,326)	681,704	84,326	1,047,705
Increase (Decrease) in Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	19,896	9,968								9,928
Distributions to noncontrolling interests		(9,957)								(9,060)	(9,060)
Acquisitions of noncontrolling interests		(3,599)
Adjustments to redemption amount of redeemable noncontrolling interests		11,818							(11,818)		(11,818)
Redeemable noncontrolling interests at Oct. 31, 2016	99,512	99,512
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	200,755							14,770	185,985
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	22,601	11,637								10,964
Comprehensive Income (Loss)	223,356										211,719
Cash dividends									(12,807)		(12,807)
Stock Issued During Period, Value, Stock Dividend			68	101
Adjustments to Additional Paid in Capital, Stock Split					(169)
Dividends, Common Stock, Stock									(23)		(23)
Issuance of common stock to HEICO Savings and Investment Plan					7,517						7,517
Share-based compensation expense					7,415						7,415
Proceeds from stock option exercises				3	5,656						5,659
Distributions to noncontrolling interests		(10,323)								(8,078)	(8,078)
Adjustments to redemption amount of redeemable noncontrolling interests		10,806							(10,806)		(10,806)
Deferred Compensation Obligation						658
Stock Held During Period Value Deferred Compensation Obligation							(658)
Adjustment from the Redemption of Noncontrolling Interests in a Partnership									194		194
Adjustments to Additional Paid in Capital, Other					(203)						(203)
Balances 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 Temporary Equity [Roll Forward]
Comprehensive Income (Loss), Net of Tax, Attributable to Redeemable Noncontrolling Interest	22,601	11,637								10,964
Distributions to noncontrolling interests		(10,323)								$ (8,078)	(8,078)
Acquisitions of noncontrolling interests		(3,848)
Adjustments to redemption amount of redeemable noncontrolling interests		10,806							$ (10,806)		$ (10,806)
Noncontrolling interests assumed related to acquisition		23,339
Redeemable noncontrolling interests at Oct. 31, 2017	$ 131,123	$ 131,123