SHARE-BASED COMPENSATION, Options Outstanding and Exercisable (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Number Outstanding (in shares)	4,670	4,173	4,169	4,080
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 29.04	$ 22.23	$ 20.42	$ 18.08
Outstanding Weighted Average Contractual Life (in years)	5 years 1 month
Outstanding Aggregated Intrinsic Value (in dollars)	$ 253,939
Number Exercisable (in shares)	3,113
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 18.80
Exercisable Weighted Average Contractual Life (in years)	3 years 6 months
Exercisable Aggregate Intrinsic Value (in dollars)	$ 205,901
Heico Common Stock [Member]
Number Outstanding (in shares)	2,343
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 25.44
Outstanding Weighted Average Contractual Life (in years)	4 years
Outstanding Aggregated Intrinsic Value (in dollars)	$ 152,858
Number Exercisable (in shares)	1,887
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 17.82
Exercisable Weighted Average Contractual Life (in years)	2 years 11 months
Exercisable Aggregate Intrinsic Value (in dollars)	$ 137,469
Common Class A [Member]
Number Outstanding (in shares)	2,327
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 32.66
Outstanding Weighted Average Contractual Life (in years)	6 years 1 month
Outstanding Aggregated Intrinsic Value (in dollars)	$ 101,081
Number Exercisable (in shares)	1,226
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 20.30
Exercisable Weighted Average Contractual Life (in years)	4 years 3 months
Exercisable Aggregate Intrinsic Value (in dollars)	$ 68,432