RESTATEMENT OF CONSOLIDATED FINANCIAL STATEMENTS (Details 4) (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
Operating Activities:
Net income	$ (37,152)	$ 18,405	$ 29,702	$ 14,314	$ 21,967	$ 27,448	$ 25,907	$ 22,309	$ 25,269	$ 97,631	$ 86,354
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	7,345	6,417	6,879	4,718	5,717	5,843	5,465	5,832	25,359	22,857	22,341
Stock-based compensation expense	1,676	1,575							3,251
Inventory write-down	2,760								2,760
Impairment of goodwill	50,865								50,865
Deferred income taxes	(7,508)				(1,486)				(7,508)	(1,486)	2,512
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable									(18,991)	(122,984)	2,047
Inventories									(19,890)	173	4,168
Prepaid expenses and other current assets									3,867	7,432	4,882
Long-term capitalized contract costs									(42,088)	(26,875)
Accounts payable and other current liabilities									(25,637)	9,630	(1,467)
Customer advances									8,990	(55,769)	32,660
Income taxes									(19,114)	14,219	(22,144)
Other items									(409)	495	(2,259)
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(6,446)	49,141	(29,855)	(26,116)	(15,862)	1,093	(1,531)	(38,377)	(13,276)	(54,677)	129,094
Investing Activities:
Acquisition of businesses, net of cash acquired	(3,042)	(7,377)	(20,177)	(33,095)					(63,691)		(126,825)
Net additions to property, plant and equipment	(2,843)	(2,348)	(2,438)	(1,423)	(982)	(3,094)	(4,901)	(5,249)	(9,052)	(14,226)	(8,728)
Purchases of short-term investments	4	(4,054)							(4,050)
Proceeds from maturities of short-term investments						7,895	10,977	6,957		25,829	58,252
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(5,881)	(13,779)	(22,615)	(34,518)	(982)	4,801	6,076	1,708	(76,793)	11,603	(77,301)
Financing Activities:
Proceeds from short term borrowings			45,000	25,000					70,000
Principal payments on short term borrowings		(25,000)	(45,000)						(70,000)
Proceeds from long term borrowings		50,000	50,000						100,000
Principal payments on long-term debt	(136)	(134)	(4,133)	(4,140)	(138)	(137)	(138)	(4,136)	(8,543)	(4,549)	(4,555)
Contingent consideration payments related to acquisitions of businesses	(7,618)	(224)							(7,842)
Dividends paid to shareholders	(3,209)		(3,208)		(3,209)		(3,208)		(6,417)	(6,417)	(7,486)
Change in restricted cash	(54)	(20)	(313)	229			(68,584)		(158)	(68,584)
Purchases of treasury stock											(4)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(11,017)	24,622	42,346	21,089	(3,347)	(137)	(71,930)	(4,136)	77,040	(79,550)	(12,045)
Effect of exchange rates on cash	14,785	3,862	(15,387)	1,394	1,329	(5,394)	9,010	798	4,654	5,743	(6,034)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(8,559)	63,846	(25,511)	(38,151)	(18,862)	363	(58,375)	(40,007)	(8,375)	(116,881)	33,714
Cash and cash equivalents at the beginning of the year	212,451	148,605	174,116	212,267	231,129	230,766	289,141	329,148	212,267	329,148	295,434
CASH AND CASH EQUIVALENTS AT THE END OF THE YEAR	203,892	212,451	148,605	174,116	212,267	231,129	230,766	289,141	203,892	212,267	329,148
Previously Reported
Operating Activities:
Net income	(38,136)	18,388	27,210	12,519	21,143	26,774	23,448	20,739	19,981	92,104	83,904
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	7,345	6,417	6,879	4,718	5,717	5,843	5,465	5,832	25,359	22,857	22,341
Stock-based compensation expense	1,676	1,575							3,251
Inventory write-down	2,760								2,760
Impairment of goodwill	50,865								50,865
Deferred income taxes	(7,508)				(1,486)				(7,508)	(1,486)	2,512
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable									(14,588)	(118,164)	3,566
Inventories									(4,219)	(13,636)	2,442
Prepaid expenses and other current assets									3,485	7,574	5,122
Long-term capitalized contract costs									(48,645)	(26,875)
Accounts payable and other current liabilities									(27,587)	8,525	(1,547)
Customer advances									3,006	(37,999)	37,143
Income taxes									(19,027)	11,929	(23,713)
Other items									(409)	494	(2,676)
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	(6,446)	49,141	(29,855)	(26,116)	(15,862)	1,093	(1,531)	(38,377)	(13,276)	(54,677)	129,094
Investing Activities:
Acquisition of businesses, net of cash acquired	(3,042)	(7,377)	(20,177)	(33,095)					(63,691)		(126,825)
Net additions to property, plant and equipment	(2,843)	(2,348)	(2,438)	(1,423)	(982)	(3,094)	(4,901)	(5,249)	(9,052)	(14,226)	(8,728)
Purchases of short-term investments	4	(4,054)							(4,050)
Proceeds from maturities of short-term investments						7,895	10,977	6,957		25,829	58,252
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(5,881)	(13,779)	(22,615)	(34,518)	(982)	4,801	6,076	1,708	(76,793)	11,603	(77,301)
Financing Activities:
Proceeds from short term borrowings			45,000	25,000					70,000
Principal payments on short term borrowings		(25,000)	(45,000)						(70,000)
Proceeds from long term borrowings		50,000	50,000						100,000
Principal payments on long-term debt	(136)	(134)	(4,133)	(4,140)	(138)	(137)	(138)	(4,136)	(8,543)	(4,549)	(4,555)
Contingent consideration payments related to acquisitions of businesses	(7,618)	(224)							(7,842)
Dividends paid to shareholders	(3,209)		(3,208)		(3,209)		(3,208)		(6,417)	(6,417)	(7,486)
Change in restricted cash	(54)	(20)	(313)	229			(68,584)		(158)	(68,584)
Purchases of treasury stock											(4)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(11,017)	24,622	42,346	21,089	(3,347)	(137)	(71,930)	(4,136)	77,040	(79,550)	(12,045)
Effect of exchange rates on cash	14,785	3,862	(15,387)	1,394	1,329	(5,394)	9,010	798	4,654	5,743	(6,034)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(8,559)	63,846	(25,511)	(38,151)	(18,862)	363	(58,375)	(40,007)	(8,375)	(116,881)	33,714
Cash and cash equivalents at the beginning of the year	212,451	148,605	174,116	212,267	231,129	230,766	289,141	329,148	212,267	329,148	295,434
CASH AND CASH EQUIVALENTS AT THE END OF THE YEAR	203,892	212,451	148,605	174,116	212,267	231,129	230,766	289,141	203,892	212,267	329,148
Adjustments
Operating Activities:
Net income	984	17	2,492	1,795	824	674	2,459	1,570	5,288	5,527	2,450
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable									(4,403)	(4,820)	(1,519)
Inventories									15,671	13,809	1,726
Prepaid expenses and other current assets									382	(142)	(240)
Long-term capitalized contract costs									6,557
Accounts payable and other current liabilities									1,950	1,105	80
Customer advances									5,984	(17,770)	(4,483)
Income taxes									(87)	2,290	1,569
Other items										$ 1	$ (417)