QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Net sales:
Net sales	$ 363,299	$ 356,084	$ 350,648	$ 306,227	$ 328,672	$ 300,370	$ 291,421	$ 268,185	$ 1,376,258	$ 1,188,648	$ 1,132,311
Gross profit:
Gross profit	135,684	133,583	134,029	112,196	126,796	108,092	105,494	93,797
Net income from consolidated operations:
Net income from consolidated operations	49,521	46,976	43,729	35,924	44,031	38,938	38,504	32,091	176,150	153,564	138,772
Net income attributable to HEICO:
Net income attributable to HEICO	$ 44,262	$ 42,002	$ 38,657	$ 31,271	$ 38,250	$ 34,369	$ 33,105	$ 27,640	$ 156,192	$ 133,364	$ 121,293
Basic:
Basic (in dollars per share)	$ 0.66	$ 0.63	$ 0.58	$ 0.47	$ 0.57	$ 0.51	$ 0.50	$ 0.42	$ 2.33	$ 2.00	$ 1.82
Diluted:
Diluted (in dollars per share)	$ 0.65	$ 0.62	$ 0.57	$ 0.46	$ 0.56	$ 0.51	$ 0.49	$ 0.41	$ 2.29	$ 1.97	$ 1.80