SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details Textuals) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Jul. 31, 2017	Jan. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Accounting Policies [Abstract]
Common Stock Dividend Percentage Rate	25.00%			25.00%
Stockholders' Equity Note, Stock Split				The stock split was effected as of April 19, 2017 in the form of a 25% stock dividend distributed to shareholders of record as of April 7, 2017. All applicable share and per share information has been adjusted retrospectively to give effect to the 5-for-4 stock split.
New Accounting Pronouncement, Early Adoption [Line Items]
Net income attributable to HEICO	$ 45,698		$ 42,002	$ 132,311	$ 111,930
Weighted Average Number of Shares Outstanding, Diluted	86,893,000		85,348,000	86,645,000	85,102,000
Accounting Standards Update 2016-09 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense		$ 3,100		$ 3,100
Net income attributable to HEICO		$ 2,600
Weighted Average Number of Shares Outstanding, Diluted	808,000			745,000