CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated cash flows - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 37,287,000	$ 125,678,000	$ 14,912,000
Net (income) loss from discontinued operations	8,335,000	(92,423,000)	2,871,000
Net cash provided by (used in) operating activities	113,958,000	58,192,000	49,151,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(45,361,000)	(50,138,000)	(34,937,000)
Acquired business, net of cash acquired	(9,219,000)	(430,932,000)	(34,719,000)
Proceeds (payments) from sale of business	(9,500,000)	474,727,000	0
Insurance proceeds	(10,604,000)	8,254,000	0
Proceeds from sale of property, plant and equipment	280,000	663,000	143,000
Proceeds from sale of property, plant and equipment	(149,000)	0	(1,824,000)
Net cash provided by (used in) investing activities - continuing operations	(74,553,000)	2,574,000	(71,337,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Purchase of shares for treasury	(1,478,000)	(45,605,000)	(15,841,000)
Proceeds from long-term debt	201,748,000	443,058,000	233,443,000
Payments of long-term debt	(218,248,000)	(300,993,000)	(170,454,000)
Share premium payment on settled debt	0	0	(24,997,000)
Change in short-term borrowings	(366,000)	144,000	0
Financing costs	(1,090,000)	(7,793,000)	(1,548,000)
Purchase of ESOP shares	0	0	(10,908,000)
Tax effect from exercise/vesting of equity awards, net	(1,686,000)		10,908,000
Dividends	(13,676,000)	(49,797,000)	(10,325,000)
Other, net	(180,000)	51,000	(70,000)
Net cash provided by (used) in financing activities - continuing operations	(34,976,000)	39,065,000	(700,000)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	(2,123,000)	(78,927,000)	(2,150,000)
Effect of exchange rate changes on cash and equivalents	313,000	1,173,000	164,000
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	2,619,000	22,077,000	(24,872,000)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	69,758,000	47,681,000	72,553,000
CASH AND EQUIVALENTS AT END OF PERIOD	72,377,000	69,758,000	47,681,000
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	37,287,000	125,678,000	14,912,000
Net (income) loss from discontinued operations	0	0	0
Net cash provided by (used in) operating activities	42,159,000	381,417,000	(10,771,000)
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(542,000)	(544,000)	(15,000)
Acquired business, net of cash acquired	(9,219,000)	(368,936,000)	0
Proceeds (payments) from sale of business	(9,500,000)	0
Insurance proceeds	(10,604,000)	8,254,000
Proceeds from sale of property, plant and equipment	0	0	0
Proceeds from sale of property, plant and equipment	(149,000)		(1,824,000)
Net cash provided by (used in) investing activities - continuing operations	(30,014,000)	(361,226,000)	(1,839,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Purchase of shares for treasury	(1,478,000)	(45,605,000)	(15,841,000)
Proceeds from long-term debt	163,297,000	411,623,000	201,124,000
Payments of long-term debt	(173,345,000)	(269,478,000)	(149,109,000)
Share premium payment on settled debt			(24,997,000)
Change in short-term borrowings	0	0
Financing costs	(1,090,000)	(7,793,000)	(1,548,000)
Tax effect from exercise/vesting of equity awards, net	0		10,908,000
Dividends	(13,676,000)	(49,797,000)	(10,325,000)
Other, net	(180,000)	(46,405,000)	20,937,000
Net cash provided by (used) in financing activities - continuing operations	(26,472,000)	(7,455,000)	9,333,000
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 INCREASE (DECREASE) IN CASH AND EQUIVALENTS	(14,327,000)	12,736,000	(3,277,000)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	15,976,000	3,240,000	6,517,000
CASH AND EQUIVALENTS AT END OF PERIOD	1,649,000	15,976,000	3,240,000
Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	94,637,000	122,687,000	24,889,000
Net (income) loss from discontinued operations	0	(92,423,000)	(12,351,000)
Net cash provided by (used in) operating activities	41,992,000	(405,174,000)	56,320,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(38,872,000)	(41,531,000)	(27,902,000)
Acquired business, net of cash acquired	0	(4,843,000)	0
Proceeds (payments) from sale of business	0	474,727,000
Insurance proceeds	0	0
Proceeds from sale of property, plant and equipment	254,000	62,000	144,000
Proceeds from sale of property, plant and equipment	0		0
Net cash provided by (used in) investing activities - continuing operations	(38,618,000)	428,415,000	(27,758,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	0	2,125,000	0
Payments of long-term debt	(2,973,000)	(5,403,000)	(1,282,000)
Share premium payment on settled debt			0
Change in short-term borrowings	(366,000)	144,000
Financing costs	0	0	0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	0	0	0
Other, net	8,830,000	4,733,000	(34,806,000)
Net cash provided by (used) in financing activities - continuing operations	5,491,000	1,599,000	(36,088,000)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	0	(16,394,000)	(12,100,000)
Effect of exchange rate changes on cash and equivalents	(1,000)	(159,000)	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	8,864,000	8,287,000	(19,626,000)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	16,353,000	8,066,000	27,692,000
CASH AND EQUIVALENTS AT END OF PERIOD	25,217,000	16,353,000	8,066,000
Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	81,089,000	84,680,000	47,242,000
Net (income) loss from discontinued operations	8,335,000	0	15,222,000
Net cash provided by (used in) operating activities	29,807,000	108,981,000	3,602,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(5,947,000)	(8,063,000)	(7,020,000)
Acquired business, net of cash acquired	0	(57,153,000)	(34,719,000)
Proceeds (payments) from sale of business	0	0
Insurance proceeds	0	0
Proceeds from sale of property, plant and equipment	26,000	601,000	(1,000)
Proceeds from sale of property, plant and equipment	0		0
Net cash provided by (used in) investing activities - continuing operations	(5,921,000)	(64,615,000)	(41,740,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	38,451,000	29,310,000	32,319,000
Payments of long-term debt	(41,930,000)	(26,112,000)	(20,063,000)
Share premium payment on settled debt			0
Change in short-term borrowings	0	0
Financing costs	0	0	0
Tax effect from exercise/vesting of equity awards, net	(1,686,000)		0
Dividends	0	0	0
Other, net	(8,830,000)	14,691,000	13,799,000
Net cash provided by (used) in financing activities - continuing operations	(13,995,000)	17,889,000	26,055,000
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	(2,123,000)	(62,533,000)	9,950,000
Effect of exchange rate changes on cash and equivalents	314,000	1,332,000	164,000
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	8,082,000	1,054,000	(1,969,000)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	37,429,000	36,375,000	38,344,000
CASH AND EQUIVALENTS AT END OF PERIOD	45,511,000	37,429,000	36,375,000
Consolidation, Eliminations [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	(175,726,000)	(207,367,000)	(72,131,000)
Net (income) loss from discontinued operations	0	0	0
Net cash provided by (used in) operating activities	0	(27,032,000)	0
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	0	0	0
Acquired business, net of cash acquired	0	0	0
Proceeds (payments) from sale of business	0	0
Insurance proceeds	0	0
Proceeds from sale of property, plant and equipment	0	0	0
Proceeds from sale of property, plant and equipment	0		0
Net cash provided by (used in) investing activities - continuing operations	0	0	0
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	0	0	0
Payments of long-term debt	0	0	0
Share premium payment on settled debt			0
Change in short-term borrowings	0	0
Financing costs	0	0	0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	0	0	0
Other, net	0	27,032,000	0
Net cash provided by (used) in financing activities - continuing operations	0	27,032,000	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 INCREASE (DECREASE) IN CASH AND EQUIVALENTS	0	0	0
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	0	0	0
CASH AND EQUIVALENTS AT END OF PERIOD	$ 0	$ 0	$ 0