QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details Textuals) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Weighted Average Number of Shares Outstanding, Diluted									86,776,000	85,213,000	84,764,000
Net income attributable to HEICO	$ 53,674	$ 45,698	$ 45,686	$ 40,927	$ 44,262	$ 42,002	$ 38,657	$ 31,271	$ 185,985	$ 156,192	$ 133,364
Earnings Per Share, Basic	$ 0.64	$ 0.54	$ 0.54	$ 0.49	$ 0.53	$ 0.50	$ 0.46	$ 0.37	$ 2.21	$ 1.86	$ 1.60
Earnings Per Share, Diluted	$ 0.62	$ 0.53	$ 0.53	$ 0.47	$ 0.52	$ 0.49	$ 0.45	$ 0.37	$ 2.14	$ 1.83	$ 1.57
Net Income Impact From Research And Development Credits Net Of Expenses								$ 1,700
Impact from US Federal R&D Tax Credit on Earnings Per Share, Basic								$ 0.02
FY 2016 Acquisition [Member]
Business Combination, Acquisition Related Costs								$ 3,100
Impact to Net Income from Acquisition Costs, Net of Tax								$ 2,000
Impact to Net Income from Acquisition Costs, Net of Tax Per Basic and Diluted Share								$ 0.02
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				679,000					781,000
Net income attributable to HEICO				$ 2,600
Earnings Per Share, Basic and Diluted				$ 0.03