SHARE-BASED COMPENSATION, Options Outstanding and Exercisable (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Number Outstanding (in shares)	6,400	7,297	6,520	6,514
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 23.19	$ 18.58	$ 14.23	$ 13.07
Outstanding Weighted Average Contractual Life (in years)	5 years
Outstanding Aggregated Intrinsic Value (in dollars)	$ 328,976
Number Exercisable (in shares)	4,357
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 15.17
Exercisable Weighted Average Contractual Life (in years)	3 years 6 months
Exercisable Aggregate Intrinsic Value (in dollars)	$ 262,053
Heico Common Stock [Member]
Number Outstanding (in shares)	2,955
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 23.48
Outstanding Weighted Average Contractual Life (in years)	4 years 4 months 24 days
Outstanding Aggregated Intrinsic Value (in dollars)	$ 178,327
Number Exercisable (in shares)	2,197
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 14.75
Exercisable Weighted Average Contractual Life (in years)	3 years
Exercisable Aggregate Intrinsic Value (in dollars)	$ 151,756
Common Class A [Member]
Number Outstanding (in shares)	3,445
Outstanding Weighted Average Exercise Price (in dollars per share)	$ 22.94
Outstanding Weighted Average Contractual Life (in years)	5 years 6 months
Outstanding Aggregated Intrinsic Value (in dollars)	$ 150,649
Number Exercisable (in shares)	2,160
Exercisable Weighted Average Exercise Price (in dollars per share)	$ 15.59
Exercisable Weighted Average Contractual Life (in years)	4 years 1 month 6 days
Exercisable Aggregate Intrinsic Value (in dollars)	$ 110,297