CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated cash flows - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 10,803	$ 10,893	$ 5,122	$ 7,471	$ 7,948	$ 14,464	$ (25,825)	$ 3,236	$ 34,289	$ (177)	$ 3,767
Net cash provided by (used in) operating activities									76,137	93,301	85,683
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(73,620)	(77,094)	(64,441)
Acquired business, net of cash acquired									(2,225)	(62,306)	0
Intercompany distributions									0	0	0
Proceeds from Sale of Available-for-sale Securities, Equity									8,891
Purchase of securities									(8,891)	8,402	0
Proceeds from sale of property, plant and equipment									334	552	1,573
Net cash used in investing activities									(66,620)	(147,250)	(62,868)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									371	584	0
Purchase of shares for treasury									(82,343)	(79,614)	(32,521)
Proceeds from issuance of debt									233,491	691,943	303
Payments of long-term debt									(187,735)	(603,094)	(16,867)
Change in short-term borrowings									(365)	(749)	2,950
Financing costs									(1,308)	(11,298)	(833)
Purchase of ESOP shares									0	(20,000)	0
Tax effect from exercise/vesting of equity awards, net									345	273	150
Dividend									7,654	6,273	5,825
Other, net									347	298	394
Net cash used in financing activities									(44,851)	(27,930)	(52,249)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									(918)	(1,528)	(2,090)
Effect of exchange rate changes on cash and equivalents									(4,152)	(2,318)	0
NET DECREASE IN CASH AND EQUIVALENTS									(40,404)	(85,725)	(31,524)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				92,405				178,130	92,405	178,130	209,654
CASH AND EQUIVALENTS AT END OF PERIOD	52,001				92,405				52,001	92,405	178,130
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									34,289	(177)	3,767
Net cash provided by (used in) operating activities									58,760	(3,902)	(25,184)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(274)	(700)	(123)
Acquired business, net of cash acquired									0	0
Intercompany distributions									10,000	10,000	10,000
Proceeds from Sale of Available-for-sale Securities, Equity									8,891
Purchase of securities										8,402
Proceeds from sale of property, plant and equipment									0	0	0
Net cash used in investing activities									18,617	898	9,877
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									371	584
Purchase of shares for treasury									(82,343)	(79,614)	(32,521)
Proceeds from issuance of debt									124,500	659,568	0
Payments of long-term debt									(116,702)	(598,250)	(2,157)
Change in short-term borrowings									0	0	0
Financing costs									(614)	(10,763)	(833)
Purchase of ESOP shares										(20,000)
Tax effect from exercise/vesting of equity awards, net									345	273	150
Dividend									7,654	11,273	5,825
Other, net									347	298	394
Net cash used in financing activities									(81,750)	(59,177)	(40,792)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									0	0	0
Effect of exchange rate changes on cash and equivalents									0	0	0
NET DECREASE IN CASH AND EQUIVALENTS									(4,373)	(62,181)	(56,099)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				6,813				68,994	6,813	68,994	125,093
CASH AND EQUIVALENTS AT END OF PERIOD	2,440				6,813				2,440	6,813	68,994
Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									55,938	40,612	33,301
Net cash provided by (used in) operating activities									27,130	17,168	83,177
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(54,196)	(64,320)	(56,617)
Acquired business, net of cash acquired									(2,225)	2,675
Intercompany distributions									(10,000)	(10,000)	(10,000)
Proceeds from Sale of Available-for-sale Securities, Equity									0
Purchase of securities										0
Proceeds from sale of property, plant and equipment									142	360	1,404
Net cash used in investing activities									(66,279)	(71,285)	(65,213)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									0	0
Purchase of shares for treasury									0	0	0
Proceeds from issuance of debt									13,596	(102)	303
Payments of long-term debt									(1,263)	(1,135)	(1,032)
Change in short-term borrowings									0	0	0
Financing costs									(196)	0	0
Purchase of ESOP shares										0
Tax effect from exercise/vesting of equity awards, net									0	0	0
Dividend									0	5,000	0
Other, net									6,161	56,533	(26,674)
Net cash used in financing activities									18,298	60,296	(27,403)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									0	0	0
Effect of exchange rate changes on cash and equivalents									0	0	0
NET DECREASE IN CASH AND EQUIVALENTS									(20,851)	6,179	(9,439)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				31,522				25,343	31,522	25,343	34,782
CASH AND EQUIVALENTS AT END OF PERIOD	10,671				31,522				10,671	31,522	25,343
Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									54,188	40,721	26,939
Net cash provided by (used in) operating activities									(9,753)	80,035	27,690
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(19,150)	(12,074)	(7,701)
Acquired business, net of cash acquired									0	(64,981)
Intercompany distributions									0	0	0
Proceeds from Sale of Available-for-sale Securities, Equity									0
Purchase of securities										0
Proceeds from sale of property, plant and equipment									192	192	169
Net cash used in investing activities									(18,958)	(76,863)	(7,532)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									0	0
Purchase of shares for treasury									0	0	0
Proceeds from issuance of debt									95,395	32,477	0
Payments of long-term debt									(69,770)	(3,709)	(13,678)
Change in short-term borrowings									(365)	(749)	2,950
Financing costs									(498)	(535)	0
Purchase of ESOP shares										0
Tax effect from exercise/vesting of equity awards, net									0	0	0
Dividend									0	0	0
Other, net									(6,161)	(56,533)	26,674
Net cash used in financing activities									18,601	(29,049)	15,946
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									(918)	(1,528)	(2,090)
Effect of exchange rate changes on cash and equivalents									(4,152)	(2,318)	0
NET DECREASE IN CASH AND EQUIVALENTS									(15,180)	(29,723)	34,014
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				54,070				83,793	54,070	83,793	49,779
CASH AND EQUIVALENTS AT END OF PERIOD	38,890				54,070				38,890	54,070	83,793
Elimination [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									(110,126)	(81,333)	(60,240)
Net cash provided by (used in) operating activities									0	0	0
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									0	0	0
Acquired business, net of cash acquired									0	0
Intercompany distributions									0	0	0
Proceeds from Sale of Available-for-sale Securities, Equity									0
Purchase of securities										0
Proceeds from sale of property, plant and equipment									0	0	0
Net cash used in investing activities									0	0	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									0	0
Purchase of shares for treasury									0	0	0
Proceeds from issuance of debt									0	0	0
Payments of long-term debt									0	0	0
Change in short-term borrowings									0	0	0
Financing costs									0	0	0
Purchase of ESOP shares										0
Tax effect from exercise/vesting of equity awards, net									0	0	0
Dividend									0	0	0
Other, net									0	0	0
Net cash used in financing activities									0	0	0
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									0	0	0
Effect of exchange rate changes on cash and equivalents									0	0	0
NET DECREASE IN CASH AND EQUIVALENTS									0	0	0
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				$ 0				$ 0	0	0	0
CASH AND EQUIVALENTS AT END OF PERIOD	$ 0				$ 0				$ 0	$ 0	$ 0