OPERATING SEGMENTS (Last three years, segment information) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales	$ 541,529	$ 532,324	$ 515,648	$ 466,146	$ 476,884	$ 465,825	$ 430,602	$ 404,410	$ 2,055,647	$ 1,777,721	$ 1,524,813
Depreciation									25,758	23,239	21,878
Amortization									57,739	53,952	42,945
Operating income									457,097	376,245	306,658
Capital expenditures									28,938	41,871	25,998
Flight Support Group [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales									1,240,183	1,097,937	967,540
Depreciation									13,793	13,322	13,042
Amortization									19,624	19,530	18,026
Operating income									242,029	206,623	179,278
Capital expenditures									17,036	13,074	15,665
Electronic Technologies Group [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales									834,522	701,827	574,261
Depreciation									10,957	9,225	8,609
Amortization									37,131	33,339	24,167
Operating income									245,743	204,508	157,451
Capital expenditures									11,826	9,531	10,100
Other Primarily Corporate and Inter Segment [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Depreciation									1,008	692	227
Amortization									984	1,083	752
Operating income									(30,675)	(34,886)	(30,071)
Capital expenditures									76	19,266	233
Consolidation, Eliminations [Member] | Other Primarily Corporate and Inter Segment [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales									$ (19,058)	$ (22,043)	$ (16,988)