Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
CASH FLOW FROM OPERATING ACTIVITIES:
Net income	$ 65,468	$ 52,850
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Depreciation	15,363	8,803
Amortization of debt issuance costs	681	202
Amortization of deferred items	393	975
Provision for inventory obsolescence	255	195
Deferred income tax benefit	(186)	(206)
Share-based compensation expense	1,790	1,501
Other, net		(61)
Changes in assets and liabilities:
Increase in accounts receivable	(32,511)	(2,946)
Decrease in income tax receivable	1,640	8,786
Decrease in inventory	6,106	1,604
Decrease in prepaid expenses	1,378	3,608
Increase in deferred costs and other assets	(1,040)	(6,391)
Increase (decrease) in accounts payable	3,463	(4,563)
Decrease in accrued liabilities	(9,143)	(1,459)
Increase in income tax payable	3,249	2,134
Increase in deferred credits and other liabilities	843	20,094
Net cash provided by operating activities	57,749	85,126
CASH FLOW FROM INVESTING ACTIVITIES:
Capital expenditures	(257,446)	(137,193)
Proceeds from sale of assets		99
Net cash used by investing activities	(257,446)	(137,094)
CASH FLOW FROM FINANCING ACTIVITIES:
Proceeds from debt		70,000
Principal payments on notes payable	(5,461)
Proceeds from exercise of stock options	79	1,654
Net cash provided and used by financing activities	(5,382)	71,654
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(205,079)	19,686
CASH AND CASH EQUIVALENTS, at beginning of period	295,002	180,523
CASH AND CASH EQUIVALENTS, at end of period	89,923	200,209
Non-cash activities
Increase (decrease) in accounts payable and accrued liabilities related to capital expenditures	$ (83,190)	$ 6,592