Statements of Cash Flows (USD $)	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (3,246,000)	$ (9,352,000)	$ 10,222,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation	30,536,000	27,126,000	26,160,000
Noncash compensation	1,671,000	1,583,000	1,758,000
Deferred income tax expense	3,368,000	2,464,000	2,300,000
Excess tax benefit from share-based payment arrangement			(5,000)
Provision for bad debts	231,000	256,000	993,000
Other	(516,000)	(343,000)	106,000
Change in current assets and liabilities:
(Increase) decrease in accounts receivable	(30,613,000)	(17,876,000)	31,641,000
Decrease (increase) in prepaid expenses and other assets	3,402,000	(37,000)	(6,942,000)
Increase (decrease) in accounts payable	3,628,000	6,181,000	(7,960,000)
Decrease in accrued liabilities	(922,000)	(1,732,000)	(4,912,000)
Increase (decrease) in deferred revenue	9,412,000	(2,026,000)	1,237,000
Net cash provided by operating activities	16,951,000	6,244,000	54,598,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures, net of noncash capital expenditures summarized below in noncash investing activities	(58,550,000)	(18,835,000)	(4,192,000)
Acquisition of short-term investments	(2,500,000)	(14,964,000)	(25,313,000)
Proceeds from maturity of short-term investments	22,500,000	20,000,000
Proceeds from disposal of assets	741,000	434,000	124,000
Proceeds on fire insurance claim	1,392,000		2,843,000
Net cash used in investing activities	(36,417,000)	(13,365,000)	(26,538,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from note payable	16,427,000
Principal payments on note payable	(856,000)
Proceeds from exercise of stock options	297,000	4,000	416,000
Excess tax benefit from share-based payment arrangement			5,000
Net cash provided by financing activities	15,868,000	4,000	421,000
Net (decrease) increase in cash and cash equivalents	(3,598,000)	(7,117,000)	28,481,000
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	29,675,000	36,792,000	8,311,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	26,077,000	29,675,000	36,792,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest expense	115,000
Cash paid for income taxes	509,000	839,000	13,222,000
Cash received for income taxes	7,366,000	8,125,000
NONCASH INVESTING ACTIVITIES:
Accrued purchases of property and equipment	830,000	1,127,000
Equipment purchase through asset trade in		2,260,000
Equipment purchase through reduction of insurance proceeds			638,000
Unrealized gain on investments		$ 3,000	$ 31,000