RESTATEMENT OF CONSOLIDATED FINANCIAL STATEMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Restatement of Comprehensive Income
Net income	$ (37,152)	$ 18,405	$ 29,702	$ 14,314	$ 21,967	$ 27,448	$ 25,907	$ 22,309	$ 25,269	$ 97,631	$ 86,354
Other comprehensive income:
Adjustment to pension liability, net of tax	13,106				(5,585)				13,106	(5,585)	(3,285)
Foreign currency translation	16,739	(1,776)	(15,338)	1,349	7,578	(5,004)	7,975	328	974	10,877	(1,329)
Net unrealized gains/losses from cash flow hedges, net of tax	(926)	4,706	(745)	742	(598)	(1,288)	3,288	(1,160)	3,777	242	(5,618)
Net unrealized gain (loss) on available-for-sale securities, net of tax	3	(5)							(2)
Total other comprehensive income (loss)	28,922	2,925	(16,083)	2,091	1,395	(6,292)	11,263	(832)	17,855	5,534	(10,232)
Total comprehensive income	(8,230)	21,330	13,619	16,405	23,362	21,156	37,170	21,477	43,124	103,165	76,122
Previously Reported
Restatement of Comprehensive Income
Net income	(38,136)	18,388	27,210	12,519	21,143	26,774	23,448	20,739	19,981	92,104	83,904
Other comprehensive income:
Adjustment to pension liability, net of tax	13,501				(5,585)				13,501	(5,585)	(3,285)
Foreign currency translation	15,679	(1,872)	(14,608)	1,295	7,375	(4,880)	7,846	347	494	10,688	(1,250)
Net unrealized gains/losses from cash flow hedges, net of tax	(926)	4,706	(745)	742	(598)	(1,288)	3,288	(1,160)	3,777	242	(5,618)
Net unrealized gain (loss) on available-for-sale securities, net of tax	3	(5)							(2)
Total other comprehensive income (loss)	28,257	2,829	(15,353)	2,037	1,192	(6,168)	11,134	(813)	17,770	5,345	(10,153)
Total comprehensive income	(9,879)	21,217	11,857	14,556	22,335	20,606	34,582	19,926	37,751	97,449	73,751
Adjustments
Restatement of Comprehensive Income
Net income	984	17	2,492	1,795	824	674	2,459	1,570	5,288	5,527	2,450
Other comprehensive income:
Adjustment to pension liability, net of tax	(395)								(395)
Foreign currency translation	1,060	96	(730)	54	203	(124)	129	(19)	480	189	(79)
Total other comprehensive income (loss)	665	96	(730)	54	203	(124)	129	(19)	85	189	(79)
Total comprehensive income	$ 1,649	$ 113	$ 1,762	$ 1,849	$ 1,027	$ 550	$ 2,588	$ 1,551	$ 5,373	$ 5,716	$ 2,371