CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of Condensed Consolidating Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
CURRENT ASSETS
Cash and equivalents	$ 47,425	$ 72,553	$ 54,282	$ 52,001
Accounts receivable, net of allowances	252,039	233,751
Contract costs and recognized income not yet billed, net of progress payments	119,573	126,961
Inventories, net	316,830	308,869
Prepaid and other current assets	39,706	38,605
Assets of discontinued operations	215	219
Total Current Assets	775,788	780,958
PROPERTY, PLANT AND EQUIPMENT, net	408,271	405,404
GOODWILL	360,085	361,185
INTANGIBLE ASSETS, net	210,676	210,599
INTERCOMPANY RECEIVABLE	0	0
EQUITY INVESTMENTS IN SUBSIDIARIES	0	0
OTHER ASSETS	18,131	21,982
ASSETS OF DISCONTINUED OPERATIONS	1,934	1,968
Total Assets	1,774,885	1,782,096
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	16,757	22,644
Accounts payable and accrued liabilities	257,166	293,935
Liabilities of discontinued operations	1,324	1,684
Total Current Liabilities	275,247	318,263
LONG-TERM DEBT, net of debt discounts	993,576	913,914
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	126,196	137,266
LIABILITIES OF DISCONTINUED OPERATIONS	1,941	1,706
Total Liabilities	1,396,960	1,371,149
Total Shareholders’ Equity	377,925	410,947
Total Liabilities and Shareholders’ Equity	1,774,885	1,782,096
Parent Company [Member]
CURRENT ASSETS
Cash and equivalents	1,416	6,517	2,955	2,440
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	8,910	39,763
Assets of discontinued operations	0	0
Total Current Assets	10,326	46,280
PROPERTY, PLANT AND EQUIPMENT, net	804	956
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	580,832	539,938
EQUITY INVESTMENTS IN SUBSIDIARIES	827,369	824,887
OTHER ASSETS	6,502	6,529
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	1,425,833	1,418,590
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,981	3,153
Accounts payable and accrued liabilities	18,416	65,751
Liabilities of discontinued operations	0	0
Total Current Liabilities	21,397	68,904
LONG-TERM DEBT, net of debt discounts	934,876	848,589
INTERCOMPANY PAYABLES	75,291	57,648
OTHER LIABILITIES	16,344	32,502
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,047,908	1,007,643
Total Shareholders’ Equity	377,925	410,947
Total Liabilities and Shareholders’ Equity	1,425,833	1,418,590
Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	7,405	27,692	16,593	10,671
Accounts receivable, net of allowances	212,815	175,583
Contract costs and recognized income not yet billed, net of progress payments	119,255	126,961
Inventories, net	261,089	239,325
Prepaid and other current assets	18,596	31,191
Assets of discontinued operations	0	0
Total Current Assets	619,160	600,752
PROPERTY, PLANT AND EQUIPMENT, net	300,765	303,735
GOODWILL	284,875	284,875
INTANGIBLE ASSETS, net	145,734	147,960
INTERCOMPANY RECEIVABLE	768,367	713,118
EQUITY INVESTMENTS IN SUBSIDIARIES	860,369	866,595
OTHER ASSETS	5,102	12,151
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	2,984,372	2,929,186
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,333	2,307
Accounts payable and accrued liabilities	183,823	202,657
Liabilities of discontinued operations	0	0
Total Current Liabilities	186,156	204,964
LONG-TERM DEBT, net of debt discounts	17,755	18,872
INTERCOMPANY PAYABLES	811,960	737,980
OTHER LIABILITIES	102,050	114,491
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,117,921	1,076,307
Total Shareholders’ Equity	1,866,451	1,852,879
Total Liabilities and Shareholders’ Equity	2,984,372	2,929,186
Non-Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	38,604	38,344	34,734	38,890
Accounts receivable, net of allowances	57,931	63,810
Contract costs and recognized income not yet billed, net of progress payments	318	0
Inventories, net	55,838	69,544
Prepaid and other current assets	12,074	16,447
Assets of discontinued operations	215	219
Total Current Assets	164,980	188,364
PROPERTY, PLANT AND EQUIPMENT, net	106,702	100,713
GOODWILL	75,210	76,310
INTANGIBLE ASSETS, net	64,942	62,639
INTERCOMPANY RECEIVABLE	338,187	307,081
EQUITY INVESTMENTS IN SUBSIDIARIES	1,926,769	1,916,622
OTHER ASSETS	6,506	12,675
ASSETS OF DISCONTINUED OPERATIONS	1,934	1,968
Total Assets	2,685,230	2,666,372
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	11,443	17,184
Accounts payable and accrued liabilities	66,942	65,213
Liabilities of discontinued operations	1,324	1,684
Total Current Liabilities	79,709	84,081
LONG-TERM DEBT, net of debt discounts	40,945	46,453
INTERCOMPANY PAYABLES	771,288	735,053
OTHER LIABILITIES	13,860	26,574
LIABILITIES OF DISCONTINUED OPERATIONS	1,941	1,706
Total Liabilities	907,743	893,867
Total Shareholders’ Equity	1,777,487	1,772,505
Total Liabilities and Shareholders’ Equity	2,685,230	2,666,372
Elimination [Member]
CURRENT ASSETS
Cash and equivalents	0	0	$ 0	$ 0
Accounts receivable, net of allowances	(18,707)	(5,642)
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories, net	(97)	0
Prepaid and other current assets	126	(48,796)
Assets of discontinued operations	0	0
Total Current Assets	(18,678)	(54,438)
PROPERTY, PLANT AND EQUIPMENT, net	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	(1,687,386)	(1,560,137)
EQUITY INVESTMENTS IN SUBSIDIARIES	(3,614,507)	(3,608,104)
OTHER ASSETS	21	(9,373)
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	(5,320,550)	(5,232,052)
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(12,015)	(39,686)
Liabilities of discontinued operations	0	0
Total Current Liabilities	(12,015)	(39,686)
LONG-TERM DEBT, net of debt discounts	0	0
INTERCOMPANY PAYABLES	(1,658,539)	(1,530,681)
OTHER LIABILITIES	(6,058)	(36,301)
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	(1,676,612)	(1,606,668)
Total Shareholders’ Equity	(3,643,938)	(3,625,384)
Total Liabilities and Shareholders’ Equity	$ (5,320,550)	$ (5,232,052)