OPERATING SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales	$ 476,884	$ 465,825	$ 430,602	$ 404,410	$ 421,224	$ 391,500	$ 368,657	$ 343,432	$ 1,777,721	$ 1,524,813	$ 1,376,258
Depreciation									23,239	21,878	20,361
Amortization									53,952	42,945	39,916
Operating income									376,245	306,658	265,345
Capital expenditures									41,871	25,998	30,863
Total assets	2,653,396				2,512,431				2,653,396	2,512,431	1,998,412
Flight Support Group [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales									1,097,937	967,540	875,870
Depreciation									13,322	13,042	12,113
Amortization									19,530	18,026	16,590
Operating income									206,623	179,278	163,427
Capital expenditures									13,074	15,665	18,434
Total assets	1,093,858				1,042,925				1,093,858	1,042,925	877,672
Electronic Technologies Group [Member]
Segment Reporting, Reconciling Item For Operating Profit (Loss) and Capital Expenditure From Segment To Consolidated [Line Items]
Net sales									701,827	574,261	511,272
Depreciation									9,225	8,609	8,030
Amortization									33,339	24,167	22,664
Operating income									204,508	157,451	126,031
Capital expenditures									9,531	10,100	11,962
Total assets	1,391,997				1,339,363				1,391,997	1,339,363	1,015,696
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									692	227	218
Amortization									1,083	752	662
Operating income									(34,886)	(30,071)	(24,113)
Capital expenditures									19,266	233	467
Total assets	$ 167,541				$ 130,143				167,541	130,143	105,044
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									$ (22,043)	$ (16,988)	$ (10,884)