GOODWILL AND OTHER INTANGIBLE ASSETS - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Goodwill [Roll Forward]
Beginning balance			$ 100,355
Currency translation differences			(8,946)
Ending balance	91,409		91,409
Intangible Assets, Net (Including Goodwill) [Abstract]
Gross Carrying Amount	54,373		54,373		58,452
Accumulated Amortization	40,733		40,733		42,740
Intangible assets amortization expense	751	664	1,535	1,355
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2015 (remainder)	1,300		1,300
2016	1,900		1,900
2017	1,700		1,700
2018	1,300		1,300
2019	1,100		1,100
2020	1,100		1,100
Patents
Intangible Assets, Net (Including Goodwill) [Abstract]
Gross Carrying Amount	16,748		16,748		17,947
Accumulated Amortization	8,478		8,478		8,721
Customer base
Intangible Assets, Net (Including Goodwill) [Abstract]
Gross Carrying Amount	16,853		16,853		18,404
Accumulated Amortization	15,814		15,814		16,883
Other Intangible Assets
Intangible Assets, Net (Including Goodwill) [Abstract]
Gross Carrying Amount	20,772		20,772		22,101
Accumulated Amortization	16,441		16,441		17,136
Germany
Goodwill [Roll Forward]
Beginning balance			40,938
Currency translation differences			(5,678)
Ending balance	35,260		35,260
United States
Goodwill [Roll Forward]
Beginning balance			13,091
Currency translation differences			(426)
Ending balance	12,665		12,665
Rest of World
Goodwill [Roll Forward]
Beginning balance			46,326
Currency translation differences			(2,842)
Ending balance	$ 43,484		$ 43,484