CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of Condensed Consolidating Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 9,553	$ 7,596	$ 26,862	$ 24,479
Net cash provided by (used in) operating activities			65,485	59,747
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment	(16,640)	(17,295)	(59,153)	(63,247)
Acquired businesses, net of cash acquired			0	(2,726)
Acquired businesses, net of cash acquired			6,051	1,744
Investment sales			0	715
Proceeds from sale of assets			165	914
Net cash used in investing activities			(65,039)	(66,088)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of shares for treasury			(15,796)	(50,771)
Proceeds from long-term debt			211,097	263,249
Payments of long-term debt			(152,478)	(177,973)
Change in short-term borrowings			(940)	(45)
Share premium payment on settled debt			(24,997)	0
Financing costs			(363)	(4,135)
Purchase of ESOP shares			(10,908)	0
Dividends paid			(7,766)	(6,686)
Other, net			(112)	13
Net cash provided by (used in) financing activities			(2,263)	23,652
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations			(1,216)	(1,152)
Effect of exchange rate changes on cash and equivalents			(72)	456
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS			(3,105)	16,615
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD		68,616	72,553	52,001
CASH AND EQUIVALENTS AT END OF PERIOD	69,448	68,616	69,448	68,616
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	9,553	7,596	26,862	24,479
Net cash provided by (used in) operating activities			(18,837)	(13,428)
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment			(12)	(221)
Acquired businesses, net of cash acquired				0
Acquired businesses, net of cash acquired			0	0
Investment sales				715
Proceeds from sale of assets			0	0
Net cash used in investing activities			(12)	494
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of shares for treasury			(15,796)	(50,771)
Proceeds from long-term debt			200,656	238,450
Payments of long-term debt			(128,365)	(143,785)
Change in short-term borrowings			0	0
Share premium payment on settled debt			(24,997)
Financing costs			(363)	(4,028)
Purchase of ESOP shares			(10,908)
Dividends paid			(7,766)	(6,686)
Other, net			21,102	13
Net cash provided by (used in) financing activities			33,563	33,193
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			14,714	20,259
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD		22,699	6,517	2,440
CASH AND EQUIVALENTS AT END OF PERIOD	21,231		21,231
Guarantor Companies [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	13,772	28,742	41,493	51,631
Net cash provided by (used in) operating activities			40,186	54,730
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment			(36,384)	(51,494)
Acquired businesses, net of cash acquired				(2,726)
Acquired businesses, net of cash acquired			0	0
Investment sales				0
Proceeds from sale of assets			157	757
Net cash used in investing activities			(36,227)	(53,463)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of shares for treasury			0	0
Proceeds from long-term debt			0	2,336
Payments of long-term debt			(1,613)	(1,599)
Change in short-term borrowings			0	0
Share premium payment on settled debt			0
Financing costs			0	0
Purchase of ESOP shares			0
Dividends paid			0	0
Other, net			(18,488)	(3,984)
Net cash provided by (used in) financing activities			(20,101)	(3,247)
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			(16,142)	(1,980)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD		8,691	27,692	10,671
CASH AND EQUIVALENTS AT END OF PERIOD	11,550		11,550
Non-Guarantor Companies [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	13,723	30,468	41,378	53,381
Net cash provided by (used in) operating activities			44,136	18,445
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment			(22,757)	(11,532)
Acquired businesses, net of cash acquired				0
Acquired businesses, net of cash acquired			6,051	1,744
Investment sales				0
Proceeds from sale of assets			8	157
Net cash used in investing activities			(28,800)	(13,119)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of shares for treasury			0	0
Proceeds from long-term debt			10,441	22,463
Payments of long-term debt			(22,500)	(32,589)
Change in short-term borrowings			(940)	(45)
Share premium payment on settled debt			0
Financing costs			0	(107)
Purchase of ESOP shares			0
Dividends paid			0	0
Other, net			(2,726)	3,984
Net cash provided by (used in) financing activities			(15,725)	(6,294)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations			(1,216)	(1,152)
Effect of exchange rate changes on cash and equivalents			(72)	456
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS			(1,677)	(1,664)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD		37,226	38,344	38,890
CASH AND EQUIVALENTS AT END OF PERIOD	36,667		36,667
Elimination [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	(27,495)	(59,210)	(82,871)	(105,012)
Net cash provided by (used in) operating activities			0	0
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of property, plant and equipment			0	0
Acquired businesses, net of cash acquired				0
Acquired businesses, net of cash acquired			0	0
Investment sales				0
Proceeds from sale of assets			0	0
Net cash used in investing activities			0	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of shares for treasury			0	0
Proceeds from long-term debt			0	0
Payments of long-term debt			0	0
Change in short-term borrowings			0	0
Share premium payment on settled debt			0
Financing costs			0	0
Purchase of ESOP shares			0
Dividends paid			0	0
Other, net			0	0
Net cash provided by (used in) financing activities			0	0
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			0	0
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD		$ 0	0	$ 0
CASH AND EQUIVALENTS AT END OF PERIOD	$ 0		$ 0