FINANCING ARRANGEMENTS: (Details) (USD $)	3 Months Ended			3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended					3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Jun. 30, 2012	Sep. 30, 2012 Senior term notes outstanding under Private Shelf Agreement	Jun. 30, 2012 Senior term notes outstanding under Private Shelf Agreement	Jul. 31, 2009 Convertible senior notes year	Sep. 30, 2012 Convertible senior notes year	Sep. 30, 2011 Convertible senior notes	Jun. 30, 2012 Convertible senior notes	Sep. 30, 2012 Revolving credit facility	Jun. 30, 2012 Revolving credit facility	Sep. 30, 2012 Equipment and leasehold notes payable	Jun. 30, 2012 Equipment and leasehold notes payable	Sep. 30, 2012 Other notes payable	Jun. 30, 2012 Other notes payable
Long-term debt
Interest rate percentage, minimum				6.69%	6.69%							4.90%	4.90%		5.75%
Interest rate percentage, maximum				8.50%	8.50%							8.75%	8.75%	8.00%	8.00%
Interest rate percentage						5.00%	5.00%		5.00%
Net carrying amount of long-term debt	$ 280,061,000	$ 330,000,000	$ 287,674,000	$ 104,286,000	$ 111,429,000		$ 162,422,000	$ 157,431,000	$ 161,134,000			$ 13,219,000	$ 14,780,000	$ 134,000	$ 331,000
Less current portion	(28,883,000)		(28,937,000)	(22,100,000)	(22,100,000)
Long-term portion	251,178,000		258,737,000
Long-term debt, additional disclosures
Principal amount of long-term debt						172,500,000	172,500,000	172,500,000
Long-term debt conversion ratio						64.6726	65.2163
Principal amount applied to conversion ratio						1,000	1,000
Long-term debt conversion price (in dollars per share)						$ 15.46	$ 15.33
Convertible long-term debt amount allocated to equity						24,700,000
Fair value of long-term debt						147,800,000
Effective interest rate on the convertible debt (as a percent)						8.90%
Debt discount amortization period							5 years
Unamortized debt discount						(24,700,000)	(10,078,000)	(15,069,000)
Interest cost related to contractual interest coupon							2,156,000	2,156,000
Interest cost related to amortization of the discount	1,288,000	1,183,000					1,288,000	1,183,000
Total interest cost							3,444,000	3,339,000
Outstanding standby letters of credit										51,000,000	26,100,000
Revolving credit facility remaining borrowing capacity										349,000,000	373,900,000
Total debt
Balance at the beginning of period	287,674,000	313,411,000
Repayment of long-term debt and capital lease obligations	(8,905,000)	(9,669,000)
Amortized debt discount	1,288,000	1,183,000					1,288,000	1,183,000
Other	4,000	(910,000)
Balance at the end of period	$ 280,061,000	$ 304,015,000