CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated balance sheets - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CURRENT ASSETS
Cash and equivalents	$ 72,553	$ 52,001	$ 92,405	$ 178,130
Accounts receivable, net of allowances	233,751	218,755
Contract costs and recognized income not yet billed, net of progress payments	126,961	103,895
Inventories, net	308,869	325,809
Prepaid and other current assets	38,605	40,258
Assets of discontinued operations	219	236
Total Current Assets	780,958	740,954
PROPERTY, PLANT AND EQUIPMENT, net	405,404	379,972
GOODWILL	361,185	356,241	374,111
INTANGIBLE ASSETS, net	210,599	213,837
INTERCOMPANY RECEIVABLE	0	0
EQUITY INVESTMENTS IN SUBSIDIARIES	0	0
OTHER ASSETS	21,982	18,554
ASSETS OF DISCONTINUED OPERATIONS	1,968	3,255
Total Assets	1,782,096	1,712,813	1,808,826
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	22,644	16,593
Accounts payable and accrued liabilities	293,935	301,015
Liabilities of discontinued operations	1,684	2,229
Total Current Liabilities	318,263	319,837
LONG-TERM DEBT, net of debt discounts	913,914	826,976
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	137,266	132,096
LIABILITIES OF DISCONTINUED OPERATIONS	1,706	3,379
Total Liabilities	1,371,149	1,282,288
SHAREHOLDERS’ EQUITY	410,947	430,525	532,027	650,464
Total Liabilities and Shareholders’ Equity	1,782,096	1,712,813
Parent Company [Member]
CURRENT ASSETS
Cash and equivalents	6,517	2,440	6,813	68,994
Accounts receivable, net of allowances	0	0
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories, net	0	0
Prepaid and other current assets	39,763	8,665
Assets of discontinued operations	0	0
Total Current Assets	46,280	11,105
PROPERTY, PLANT AND EQUIPMENT, net	956	1,108
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	539,938	542,297
EQUITY INVESTMENTS IN SUBSIDIARIES	824,887	745,262
OTHER ASSETS	6,529	37,982
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	1,418,590	1,337,754
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	3,153	2,202
Accounts payable and accrued liabilities	65,751	26,365
Liabilities of discontinued operations	0	0
Total Current Liabilities	68,904	28,567
LONG-TERM DEBT, net of debt discounts	848,589	752,839
INTERCOMPANY PAYABLES	57,648	76,477
OTHER LIABILITIES	32,502	49,346
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,007,643	907,229
SHAREHOLDERS’ EQUITY	410,947	430,525
Total Liabilities and Shareholders’ Equity	1,418,590	1,337,754
Guarantor Subsidiaries [Member]
CURRENT ASSETS
Cash and equivalents	27,692	10,671	31,522	25,343
Accounts receivable, net of allowances	175,583	178,830
Contract costs and recognized income not yet billed, net of progress payments	126,961	103,879
Inventories, net	239,325	257,929
Prepaid and other current assets	31,191	27,584
Assets of discontinued operations	0	0
Total Current Assets	600,752	578,893
PROPERTY, PLANT AND EQUIPMENT, net	303,735	286,854
GOODWILL	284,875	284,875
INTANGIBLE ASSETS, net	147,960	152,412
INTERCOMPANY RECEIVABLE	713,118	904,840
EQUITY INVESTMENTS IN SUBSIDIARIES	866,595	644,577
OTHER ASSETS	12,151	30,203
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	2,929,186	2,882,654
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,307	3,842
Accounts payable and accrued liabilities	202,657	222,758
Liabilities of discontinued operations	0	0
Total Current Liabilities	204,964	226,600
LONG-TERM DEBT, net of debt discounts	18,872	17,116
INTERCOMPANY PAYABLES	737,980	831,345
OTHER LIABILITIES	114,491	126,956
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,076,307	1,202,017
SHAREHOLDERS’ EQUITY	1,852,879	1,680,637
Total Liabilities and Shareholders’ Equity	2,929,186	2,882,654
Non-Guarantor Subsidiaries [Member]
CURRENT ASSETS
Cash and equivalents	38,344	38,890	54,070	83,793
Accounts receivable, net of allowances	63,810	61,772
Contract costs and recognized income not yet billed, net of progress payments	0	16
Inventories, net	69,544	67,880
Prepaid and other current assets	16,447	12,488
Assets of discontinued operations	219	236
Total Current Assets	188,364	181,282
PROPERTY, PLANT AND EQUIPMENT, net	100,713	92,010
GOODWILL	76,310	71,366
INTANGIBLE ASSETS, net	62,639	61,425
INTERCOMPANY RECEIVABLE	307,081	263,480
EQUITY INVESTMENTS IN SUBSIDIARIES	1,916,622	1,740,889
OTHER ASSETS	12,675	9,959
ASSETS OF DISCONTINUED OPERATIONS	1,968	3,255
Total Assets	2,666,372	2,423,666
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	17,184	10,549
Accounts payable and accrued liabilities	65,213	72,843
Liabilities of discontinued operations	1,684	2,229
Total Current Liabilities	84,081	85,621
LONG-TERM DEBT, net of debt discounts	46,453	57,021
INTERCOMPANY PAYABLES	735,053	775,120
OTHER LIABILITIES	26,574	28,428
LIABILITIES OF DISCONTINUED OPERATIONS	1,706	3,379
Total Liabilities	893,867	949,569
SHAREHOLDERS’ EQUITY	1,772,505	1,474,097
Total Liabilities and Shareholders’ Equity	2,666,372	2,423,666
Consolidation, Eliminations [Member]
CURRENT ASSETS
Cash and equivalents	0	0	$ 0	$ 0
Accounts receivable, net of allowances	(5,642)	(21,847)
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories, net	0	0
Prepaid and other current assets	(48,796)	(8,479)
Assets of discontinued operations	0	0
Total Current Assets	(54,438)	(30,326)
PROPERTY, PLANT AND EQUIPMENT, net	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	(1,560,137)	(1,710,617)
EQUITY INVESTMENTS IN SUBSIDIARIES	(3,608,104)	(3,130,728)
OTHER ASSETS	(9,373)	(59,590)
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	(5,232,052)	(4,931,261)
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(39,686)	(20,951)
Liabilities of discontinued operations	0	0
Total Current Liabilities	(39,686)	(20,951)
LONG-TERM DEBT, net of debt discounts	0	0
INTERCOMPANY PAYABLES	(1,530,681)	(1,682,942)
OTHER LIABILITIES	(36,301)	(72,634)
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	(1,606,668)	(1,776,527)
SHAREHOLDERS’ EQUITY	(3,625,384)	(3,154,734)
Total Liabilities and Shareholders’ Equity	$ (5,232,052)	$ (4,931,261)