CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated cash flows - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 7,723	$ 7,596	$ 6,095	$ 8,596	$ 10,803	$ 10,893	$ 5,122	$ 7,471	$ 30,010	$ 34,289	$ (177)
Net cash provided by (used in) operating activities									105,937	76,137	93,301
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(90,759)	(73,620)	(77,094)
Acquired business, net of cash acquired									(4,470)	(2,225)	(62,306)
Intercompany distributions										0	0
Investment sales (purchases)									715	8,891	(8,402)
Proceeds from sale of property, plant and equipment									909	334	552
Net cash used in investing activities									(93,605)	(66,620)	(147,250)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock									0	371	584
Purchase of shares for treasury									(65,307)	(82,343)	(79,614)
Proceeds from issuance of debt									302,362	233,491	691,943
Payments of long-term debt									(214,986)	(187,735)	(603,094)
Change in short-term borrowings									(54)	(365)	(749)
Financing costs									(4,384)	(1,308)	(11,298)
Purchase of ESOP shares									0	0	(20,000)
Tax effect from exercise/vesting of equity awards, net									0	345	273
Dividends									(8,798)	(7,654)	(6,273)
Other, net									55	347	298
Net cash used in financing activities									8,888	(44,851)	(27,930)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations									(1,554)	(918)	(1,528)
Effect of exchange rate changes on cash and equivalents									886	(4,152)	(2,318)
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS									20,552	(40,404)	(85,725)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				52,001				92,405	52,001	92,405	178,130
CASH AND EQUIVALENTS AT END OF PERIOD	72,553				52,001				72,553	52,001	92,405
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									30,010	34,289	(177)
Net cash provided by (used in) operating activities									(11,879)	58,760	(3,902)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment										(274)	(700)
Acquired business, net of cash acquired										0	0
Intercompany distributions										10,000	10,000
Investment sales (purchases)									715	8,891	(8,402)
Proceeds from sale of property, plant and equipment										0	0
Net cash used in investing activities										18,617	898
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock										371	584
Purchase of shares for treasury										(82,343)	(79,614)
Proceeds from issuance of debt										124,500	659,568
Payments of long-term debt										(116,702)	(598,250)
Change in short-term borrowings									0	0	0
Financing costs									(4,277)	(614)	(10,763)
Purchase of ESOP shares											(20,000)
Tax effect from exercise/vesting of equity awards, net										345	273
Dividends										(7,654)	(11,273)
Other, net										347	298
Net cash used in financing activities										(81,750)	(59,177)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations										0	0
Effect of exchange rate changes on cash and equivalents										0	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS										(4,373)	(62,181)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				2,440				6,813	2,440	6,813	68,994
CASH AND EQUIVALENTS AT END OF PERIOD	6,517				2,440				6,517	2,440	6,813
Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									50,571	55,938	40,612
Net cash provided by (used in) operating activities										27,130	17,168
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment									(78,159)	(54,196)	(64,320)
Acquired business, net of cash acquired										(2,225)	2,675
Intercompany distributions										(10,000)	(10,000)
Investment sales (purchases)									0	0	0
Proceeds from sale of property, plant and equipment									765	142	360
Net cash used in investing activities										(66,279)	(71,285)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock										0	0
Purchase of shares for treasury										0	0
Proceeds from issuance of debt										13,596	(102)
Payments of long-term debt										(1,263)	(1,135)
Change in short-term borrowings										0	0
Financing costs										(196)	0
Purchase of ESOP shares											0
Tax effect from exercise/vesting of equity awards, net										0	0
Dividends										0	5,000
Other, net										6,161	56,533
Net cash used in financing activities										18,298	60,296
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations										0	0
Effect of exchange rate changes on cash and equivalents									0	0	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS									17,021	(20,851)	6,179
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				10,671				31,522	10,671	31,522	25,343
CASH AND EQUIVALENTS AT END OF PERIOD	27,692				10,671				27,692	10,671	31,522
Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									52,316	54,188	40,721
Net cash provided by (used in) operating activities										(9,753)	80,035
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment										(19,150)	(12,074)
Acquired business, net of cash acquired										0	(64,981)
Intercompany distributions										0	0
Investment sales (purchases)									0	0	0
Proceeds from sale of property, plant and equipment										192	192
Net cash used in investing activities									(13,941)	(18,958)	(76,863)
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
Payments of long-term debt									(35,338)	(69,770)	(3,709)
Change in short-term borrowings									(54)	(365)	(749)
Financing costs										(498)	(535)
Purchase of ESOP shares											0
Tax effect from exercise/vesting of equity awards, net										0	0
Dividends									0	0	0
Other, net										(6,161)	(56,533)
Net cash used in financing activities									(4,862)	18,601	(29,049)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations										(918)	(1,528)
Effect of exchange rate changes on cash and equivalents										(4,152)	(2,318)
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS									(546)	(15,180)	(29,723)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD				38,890				54,070	38,890	54,070	83,793
CASH AND EQUIVALENTS AT END OF PERIOD	38,344				38,890				38,344	38,890	54,070
Consolidation, Eliminations [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)									(102,887)	(110,126)	(81,333)
Net cash provided by (used in) operating activities										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
Investment sales (purchases)									0	0	0
Proceeds from sale of property, plant and equipment										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
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
Purchase of ESOP shares											0
Tax effect from exercise/vesting of equity awards, net										0	0
Dividends										0	0
Other, net										0	0
Net cash used in financing activities										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
NET INCREASE (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