QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details Textuals) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Remeasurement of Deferred Tax Liabilities for Change in Tax Rate, Net	$ 11,900								$ 11,900
Remeasurement of Deferred Tax Liabilities for Change in Tax Rate, Net, Per Share	$ 0.09								$ 0.09
Weighted Average Number of Shares Outstanding, Diluted									136,696,000	135,588,000	133,145,000
Net income attributable to HEICO	$ 67,377	$ 67,086	$ 59,618	$ 65,152	$ 53,674	$ 45,698	$ 45,686	$ 40,927	$ 259,233	$ 185,985	$ 156,192
Earnings Per Share, Basic	$ 0.51	$ 0.51	$ 0.45	$ 0.49	$ 0.41	$ 0.35	$ 0.35	$ 0.31	$ 1.96	$ 1.41	$ 1.19
Earnings Per Share, Diluted	$ 0.49	$ 0.49	$ 0.44	$ 0.48	$ 0.39	$ 0.34	$ 0.34	$ 0.30	$ 1.90	$ 1.37	$ 1.17
Accounting Standards Update 2016-09 [Member]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense								$ 3,100
Weighted Average Number of Shares Outstanding, Diluted								1,220,000
Net income attributable to HEICO								$ 2,600
Earnings Per Share, Basic								$ 0.02
Earnings Per Share, Diluted								$ 0.01