Consolidated Statements of Cash Flows (USD $)	9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 13,270,000	$ 9,961,000	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	27,913,000	24,092,000
Noncash compensation	1,481,000	1,037,000
Deferred income tax expense	8,035,000	4,335,000
Provision for bad debts		325,000
Other	299,000	161,000
Change in current assets and liabilities:
Decrease in accounts receivable	6,335,000	30,374,000
Increase in prepaid expenses and other assets	(1,645,000)	(916,000)
Decrease in accounts payable	(6,020,000)	(3,945,000)
Increase (decrease) in accrued liabilities	1,682,000	(2,124,000)
Decrease in deferred revenue	(1,757,000)	(5,296,000)
Net cash provided by operating activities	49,593,000	58,004,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures, net of noncash capital expenditures summarized below in noncash investing and financing activities	(45,454,000)	(28,962,000)
Proceeds from maturity of short-term investments	6,000,000
Acquisition of short-term investments	(20,000,000)	(2,750,000)
Proceeds from disposal of assets	248,000	252,000
Net cash used by investing activities	(59,206,000)	(31,460,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from note payable	983,000
Principal payments on notes payable	(6,609,000)	(3,948,000)
Principal payments on capital lease obligations	(531,000)	(118,000)
Proceeds from exercise of stock options	437,000	184,000
Net cash used by financing activities	(5,720,000)	(3,882,000)
Net (decrease) increase in cash and cash equivalents	(15,333,000)	22,662,000
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	57,373,000	26,077,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	42,040,000	48,739,000
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest	545,000	436,000
Cash paid for income taxes	1,557,000	262,000
Cash received for income taxes	33,000	137,000
NONCASH INVESTING AND FINANCING ACTIVITIES:
Increase in accrued purchases of property and equipment	357,000	12,156,000
Capital lease obligations incurred	$ 1,296,000	$ 1,427,000

[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 nine months ended June 30, 2012 was $0.15 and $1.27, respectively. Diluted earnings per share as previously reported for the quarter and nine months ended June 30, 2012 was $0.14 and $1.26, respectively. Basic weighted average shares outstanding as previously reported for the quarter and nine months ended June 30, 2012 were 7,846,417 and 7,839,983, respectively. Diluted weighted average shares outstanding as previously reported for the quarter and nine months ended June 30, 2012 were 7,924,009 and 7,934,367, respectively. The impact on all prior period financial statements is deemed immaterial.