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, 2015			$ 269	$ 400	$ 286,220	$ 1,783	$ (1,783)	$ (25,080)	$ 548,054	$ 83,408	$ 893,271
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 SIP			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)
Acquisitions of noncontrolling interests		3,599
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			270	403	306,328	2,460	(2,460)	(25,326)	681,704	84,326	1,047,705
Redeemable noncontrolling interests at Oct. 31, 2015		91,282
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
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 SIP					7,517						7,517
Share-based Compensation Expense					7,415						7,415
Proceeds from stock option exercises				3	5,656						5,659
Noncontrolling interests assumed related to acquisition		(23,339)
Distributions to noncontrolling interests		(10,323)								(8,078)	(8,078)
Acquisitions of noncontrolling interests		3,848							194		194
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)
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
Noncontrolling interests assumed related to acquisition		23,339
Distributions to noncontrolling interests		(10,323)								(8,078)	(8,078)
Acquisitions of noncontrolling interests		(3,848)							(194)		(194)
Adjustments to redemption amount of redeemable noncontrolling interests		10,806							(10,806)		(10,806)
Redeemable noncontrolling interests at Oct. 31, 2017	131,123	131,123
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	4,022						4,031
Redemption of common stock related to stock option exercises			(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	1,503,008		$ 534	$ 796	$ 320,994	$ 3,928	$ (3,928)	$ (15,256)	1,091,183	104,757	1,503,008
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	$ 132,046