OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Summary of Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments, Pre-tax	$ (56,358)	$ (23,933)	$ (3,090)
Pension and other defined benefit plans, Pre-tax	(6,655)	(6,061)	32,431
Cash flow hedge, Pre-tax	662	386	0
Available-for-sale securities, Pre-tax	(1,370)	1,370	0
Total other comprehensive income (loss), Pre-tax	(63,721)	(28,238)	29,341
Foreign currency translation adjustments, Tax	0	0	0
Pension and other defined benefit plans, Tax	2,329	2,147	(13,121)
Cash flow hedge, Tax	(232)	(134)	0
Available-for-sale securities, Tax	500	(500)	0
Total other comprehensive income (loss), Tax	2,597	1,513	(13,121)
Foreign currency translation adjustments, Net of Tax	(56,358)	(23,933)	(3,090)
Pension and other defined benefit plans, Net of Tax	(4,326)	(3,914)	19,310
Cash flow hedge, Net of Tax	430	252	0
Available-for-sale securities, Net of Tax	(870)	870	0
Total other comprehensive income (loss), net of taxes	$ (61,124)	$ (26,725)	$ 16,220