CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of Condensed Consolidating Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
CURRENT ASSETS
Cash and equivalents	$ 52,269	$ 72,553	$ 49,968	$ 52,001
Accounts receivable, net of allowances	228,025	233,751
Contract costs and recognized income not yet billed, net of progress payments	108,572	126,961
Inventories, net	323,192	308,869
Prepaid and other current assets	41,410	38,605
Assets of discontinued operations	218	219
Total Current Assets	753,686	780,958
PROPERTY, PLANT AND EQUIPMENT, net	400,151	405,404
GOODWILL	357,507	361,185
INTANGIBLE ASSETS, net	210,251	210,599
INTERCOMPANY RECEIVABLE	0	0
EQUITY INVESTMENTS IN SUBSIDIARIES	0	0
OTHER ASSETS	21,634	21,982
ASSETS OF DISCONTINUED OPERATIONS	1,960	1,968
Total Assets	1,745,189	1,782,096
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	26,347	22,644
Accounts payable and accrued liabilities	256,734	293,935
Liabilities of discontinued operations	1,498	1,684
Total Current Liabilities	284,579	318,263
LONG-TERM DEBT, net of debt discounts	938,673	913,914
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	130,818	137,266
LIABILITIES OF DISCONTINUED OPERATIONS	2,098	1,706
Total Liabilities	1,356,168	1,371,149
Total Shareholders’ Equity	389,021	410,947
Total Liabilities and Shareholders’ Equity	1,745,189	1,782,096
Parent Company [Member]
CURRENT ASSETS
Cash and equivalents	1,726	6,517	3,589	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	39,453	39,763
Assets of discontinued operations	0	0
Total Current Assets	41,179	46,280
PROPERTY, PLANT AND EQUIPMENT, net	878	956
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	554,518	539,938
EQUITY INVESTMENTS IN SUBSIDIARIES	826,587	824,887
OTHER ASSETS	6,773	6,529
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	1,429,935	1,418,590
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	3,067	3,153
Accounts payable and accrued liabilities	63,239	65,751
Liabilities of discontinued operations	0	0
Total Current Liabilities	66,306	68,904
LONG-TERM DEBT, net of debt discounts	881,781	848,589
INTERCOMPANY PAYABLES	64,051	57,648
OTHER LIABILITIES	28,776	32,502
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,040,914	1,007,643
Total Shareholders’ Equity	389,021	410,947
Total Liabilities and Shareholders’ Equity	1,429,935	1,418,590
Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	13,749	27,692	12,108	10,671
Accounts receivable, net of allowances	178,803	175,583
Contract costs and recognized income not yet billed, net of progress payments	108,028	126,961
Inventories, net	262,141	239,325
Prepaid and other current assets	33,165	31,191
Assets of discontinued operations	0	0
Total Current Assets	595,886	600,752
PROPERTY, PLANT AND EQUIPMENT, net	301,822	303,735
GOODWILL	284,875	284,875
INTANGIBLE ASSETS, net	146,847	147,960
INTERCOMPANY RECEIVABLE	882,627	713,118
EQUITY INVESTMENTS IN SUBSIDIARIES	866,959	866,595
OTHER ASSETS	11,802	12,151
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	3,090,818	2,929,186
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,320	2,307
Accounts payable and accrued liabilities	178,179	202,657
Liabilities of discontinued operations	0	0
Total Current Liabilities	180,499	204,964
LONG-TERM DEBT, net of debt discounts	18,316	18,872
INTERCOMPANY PAYABLES	921,844	737,980
OTHER LIABILITIES	112,763	114,491
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,233,422	1,076,307
Total Shareholders’ Equity	1,857,396	1,852,879
Total Liabilities and Shareholders’ Equity	3,090,818	2,929,186
Non-Guarantor Companies [Member]
CURRENT ASSETS
Cash and equivalents	36,794	38,344	34,271	38,890
Accounts receivable, net of allowances	57,055	63,810
Contract costs and recognized income not yet billed, net of progress payments	544	0
Inventories, net	61,051	69,544
Prepaid and other current assets	17,524	16,447
Assets of discontinued operations	218	219
Total Current Assets	173,186	188,364
PROPERTY, PLANT AND EQUIPMENT, net	97,451	100,713
GOODWILL	72,632	76,310
INTANGIBLE ASSETS, net	63,404	62,639
INTERCOMPANY RECEIVABLE	322,103	307,081
EQUITY INVESTMENTS IN SUBSIDIARIES	1,921,056	1,916,622
OTHER ASSETS	14,124	12,675
ASSETS OF DISCONTINUED OPERATIONS	1,960	1,968
Total Assets	2,665,916	2,666,372
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	20,960	17,184
Accounts payable and accrued liabilities	56,382	65,213
Liabilities of discontinued operations	1,498	1,684
Total Current Liabilities	78,840	84,081
LONG-TERM DEBT, net of debt discounts	38,576	46,453
INTERCOMPANY PAYABLES	758,271	735,053
OTHER LIABILITIES	21,060	26,574
LIABILITIES OF DISCONTINUED OPERATIONS	2,098	1,706
Total Liabilities	898,845	893,867
Total Shareholders’ Equity	1,767,071	1,772,505
Total Liabilities and Shareholders’ Equity	2,665,916	2,666,372
Elimination [Member]
CURRENT ASSETS
Cash and equivalents	0	0	$ 0	$ 0
Accounts receivable, net of allowances	(7,833)	(5,642)
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories, net	0	0
Prepaid and other current assets	(48,732)	(48,796)
Assets of discontinued operations	0	0
Total Current Assets	(56,565)	(54,438)
PROPERTY, PLANT AND EQUIPMENT, net	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	(1,759,248)	(1,560,137)
EQUITY INVESTMENTS IN SUBSIDIARIES	(3,614,602)	(3,608,104)
OTHER ASSETS	(11,065)	(9,373)
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	(5,441,480)	(5,232,052)
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(41,066)	(39,686)
Liabilities of discontinued operations	0	0
Total Current Liabilities	(41,066)	(39,686)
LONG-TERM DEBT, net of debt discounts	0	0
INTERCOMPANY PAYABLES	(1,744,166)	(1,530,681)
OTHER LIABILITIES	(31,781)	(36,301)
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	(1,817,013)	(1,606,668)
Total Shareholders’ Equity	(3,624,467)	(3,625,384)
Total Liabilities and Shareholders’ Equity	$ (5,441,480)	$ (5,232,052)