CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of Condensed Consolidating Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2013
CURRENT ASSETS
Cash and equivalents	$ 54,282	$ 52,001	$ 42,602	$ 92,405	$ 92,405
Accounts receivable, net of allowances	261,161	218,755
Contract costs and recognized income not yet billed, net of progress payments	108,480	103,895
Inventories, net	311,567	325,809
Prepaid and other current assets	53,022	55,086
Assets of discontinued operations	1,325	1,316
Total Current Assets	789,837	756,862
PROPERTY, PLANT AND EQUIPMENT, net	386,109	379,972
GOODWILL	360,094	356,241
INTANGIBLE ASSETS, net	214,733	213,837
INTERCOMPANY RECEIVABLE	0	0
EQUITY INVESTMENTS IN SUBSIDIARIES	0	0
OTHER ASSETS	25,482	22,346
ASSETS OF DISCONTINUED OPERATIONS	2,259	2,175
Total Assets	1,778,514	1,731,433
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	19,217	16,593
Accounts payable and accrued liabilities	260,626	304,808
Liabilities of discontinued operations	1,924	2,229
Total Current Liabilities	281,767	323,630
LONG-TERM DEBT, net of debt discounts	922,563	826,976
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	145,583	146,923
LIABILITIES OF DISCONTINUED OPERATIONS	3,220	3,379
Total Liabilities	1,353,133	1,300,908
Total Shareholders’ Equity	425,381	430,525
Total Liabilities and Shareholders’ Equity	1,778,514	1,731,433
Parent Company [Member]
CURRENT ASSETS
Cash and equivalents	2,955	2,440	3,174	6,813
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	25,050	23,493
Assets of discontinued operations	0	0
Total Current Assets	28,005	25,933
PROPERTY, PLANT AND EQUIPMENT, net	1,095	1,108
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	593,980	542,297
EQUITY INVESTMENTS IN SUBSIDIARIES	776,215	745,262
OTHER ASSETS	41,813	41,774
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	1,441,108	1,356,374
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,736	2,202
Accounts payable and accrued liabilities	36,674	30,158
Liabilities of discontinued operations	0	0
Total Current Liabilities	39,410	32,360
LONG-TERM DEBT, net of debt discounts	848,962	752,839
INTERCOMPANY PAYABLES	68,143	76,477
OTHER LIABILITIES	59,212	64,173
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,015,727	925,849
Total Shareholders’ Equity	425,381	430,525
Total Liabilities and Shareholders’ Equity	1,441,108	1,356,374
Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	16,593	10,671	10,803	31,522
Accounts receivable, net of allowances	229,666	178,830
Contract costs and recognized income not yet billed, net of progress payments	107,937	103,879
Inventories, net	235,067	257,929
Prepaid and other current assets	25,906	27,584
Assets of discontinued operations	0	0
Total Current Assets	615,169	578,893
PROPERTY, PLANT AND EQUIPMENT, net	287,972	286,854
GOODWILL	284,875	284,875
INTANGIBLE ASSETS, net	150,186	152,412
INTERCOMPANY RECEIVABLE	841,728	904,840
EQUITY INVESTMENTS IN SUBSIDIARIES	651,130	644,577
OTHER ASSETS	32,858	30,203
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	2,863,918	2,882,654
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,304	3,842
Accounts payable and accrued liabilities	184,884	222,758
Liabilities of discontinued operations	0	0
Total Current Liabilities	187,188	226,600
LONG-TERM DEBT, net of debt discounts	19,972	17,116
INTERCOMPANY PAYABLES	821,631	831,345
OTHER LIABILITIES	124,681	126,956
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,153,472	1,202,017
Total Shareholders’ Equity	1,710,446	1,680,637
Total Liabilities and Shareholders’ Equity	2,863,918	2,882,654
Non-Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	34,734	38,890	28,625	54,070
Accounts receivable, net of allowances	59,488	61,772
Contract costs and recognized income not yet billed, net of progress payments	543	16
Inventories, net	76,500	67,880
Prepaid and other current assets	12,752	12,488
Assets of discontinued operations	1,325	1,316
Total Current Assets	185,342	182,362
PROPERTY, PLANT AND EQUIPMENT, net	97,042	92,010
GOODWILL	75,219	71,366
INTANGIBLE ASSETS, net	64,547	61,425
INTERCOMPANY RECEIVABLE	287,600	263,480
EQUITY INVESTMENTS IN SUBSIDIARIES	1,770,747	1,740,889
OTHER ASSETS	11,592	9,959
ASSETS OF DISCONTINUED OPERATIONS	2,259	2,175
Total Assets	2,494,348	2,423,666
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	14,177	10,549
Accounts payable and accrued liabilities	73,282	72,843
Liabilities of discontinued operations	1,924	2,229
Total Current Liabilities	89,383	85,621
LONG-TERM DEBT, net of debt discounts	53,629	57,021
INTERCOMPANY PAYABLES	804,601	775,120
OTHER LIABILITIES	33,907	28,428
LIABILITIES OF DISCONTINUED OPERATIONS	3,220	3,379
Total Liabilities	984,740	949,569
Total Shareholders’ Equity	1,509,608	1,474,097
Total Liabilities and Shareholders’ Equity	2,494,348	2,423,666
Elimination [Member]
CURRENT ASSETS
Cash and equivalents	0	0	$ 0	$ 0
Accounts receivable, net of allowances	(27,993)	(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	(10,686)	(8,479)
Assets of discontinued operations	0	0
Total Current Assets	(38,679)	(30,326)
PROPERTY, PLANT AND EQUIPMENT, net	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	(1,723,308)	(1,710,617)
EQUITY INVESTMENTS IN SUBSIDIARIES	(3,198,092)	(3,130,728)
OTHER ASSETS	(60,781)	(59,590)
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	(5,020,860)	(4,931,261)
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(34,214)	(20,951)
Liabilities of discontinued operations	0	0
Total Current Liabilities	(34,214)	(20,951)
LONG-TERM DEBT, net of debt discounts	0	0
INTERCOMPANY PAYABLES	(1,694,375)	(1,682,942)
OTHER LIABILITIES	(72,217)	(72,634)
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	(1,800,806)	(1,776,527)
Total Shareholders’ Equity	(3,220,054)	(3,154,734)
Total Liabilities and Shareholders’ Equity	$ (5,020,860)	$ (4,931,261)