CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 9,207,000	$ 8,820,000	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	18,682,000	15,764,000
Noncash compensation	995,000	712,000
Deferred income tax expense	5,542,000	3,259,000
Provision for bad debts	62,000	315,000
Other	100,000	117,000
Change in current assets and liabilities:
(Increase) decrease in accounts receivable	(13,390,000)	1,089,000
Increase in prepaid expenses and other assets	(3,007,000)	(1,716,000)
Decrease in accounts payable	(4,843,000)	(1,665,000)
Increase (decrease) in accrued liabilities	409,000	(2,359,000)
Decrease in deferred revenue	(1,344,000)	(3,430,000)
Net cash provided by operating activities	12,413,000	20,906,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures, net of noncash capital expenditures summarized below in noncash investing and financing activities	(40,147,000)	(19,688,000)
Proceeds from maturity of short-term investments	3,000,000
Acquisition of short-term investments	(11,750,000)
Proceeds from disposal of assets	211,000	219,000
Net cash used by investing activities	(48,686,000)	(19,469,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from note payable	983,000
Principal payments on notes payable	(4,343,000)	(2,620,000)
Principal payments on capital lease obligations	(329,000)	(18,000)
Proceeds from exercise of stock options	241,000	184,000
Net cash used by financing activities	(3,448,000)	(2,454,000)
Net decrease in cash and cash equivalents	(39,721,000)	(1,017,000)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	57,373,000	26,077,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	17,652,000	25,060,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest	377,000	296,000
Cash paid for income taxes	882,000	1,000
Cash received for income taxes	33,000	137,000
NONCASH INVESTING AND FINANCING ACTIVITIES:
Accrued purchases of property and equipment	2,273,000	57,000
Capital lease obligations incurred	$ 1,296,000	$ 1,262,000

[1] Prior year earnings per share calculations have been adjusted for the two-class method to reflect restricted shares that were not reflected as participating in prior periods. Basic earnings per share as previously reported for the quarter and six months ended March 31, 2012 was $0.71 and $1.13, respectively. Diluted earnings per share as previously reported for the quarter and six months ended March 31, 2012 was $0.70 and $1.11, respectively. Basic weighted average shares outstanding as previously reported for the quarter and six months ended March 31, 2012 were 7,841,362 and 7,836,787, respectively. Diluted weighted average shares outstanding as previously reported for the quarter and six months ended March 31, 2012 were 7,953,141 and 7,938,166, respectively. The impact on all prior period financial statements is deemed immaterial.