ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Components of Accumulated Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			$ 497,648
Foreign currency translation adjustments, net of tax	$ (2,635)	$ 3,795	(6,326)	$ 10,152
Change in fair value, net of tax			1,088	(164)
Reclassification adjustment into earnings, net of tax			(269)	(101)
Change in pension and other postretirement liabilities, net of tax of $0	0	0	0	287
Balance, end of period	575,022		575,022
Other Comprehensive Income (Loss), Tax [Abstract]
Foreign currency translation adjustment, tax			(1,814)	1,613
Change in fair value, tax			610	(90)
Reclassification adjustment into earnings, tax			(150)	(56)
Change in pension and other postretirement liabilities, tax			0	287
Accumulated Other Comprehensive Income (Loss) [Member]
Components of Accumulated Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			9,556	(6,090)
Balance, end of period	4,049	4,084	4,049	4,084
Foreign Currency Translation Adjustment [Member]
Components of Accumulated Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			11,985	(4,011)
Foreign currency translation adjustments, net of tax			(6,326)	10,152
Balance, end of period	5,659	6,141	5,659	6,141
Cash Flow Hedges [Member]
Components of Accumulated Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			(817)	(901)
Change in fair value, net of tax			1,088	(164)
Reclassification adjustment into earnings, net of tax			(269)	(101)
Balance, end of period	2	(1,166)	2	(1,166)
Pension and Other Postretirement Liabilities [Member]
Components of Accumulated Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			(1,612)	(1,178)
Change in pension and other postretirement liabilities, net of tax of $0				287
Balance, end of period	$ (1,612)	$ (891)	$ (1,612)	$ (891)