Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 158,350	$ 124,934
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	56,060	30,769
Amortization of debt issuance costs	2,073	1,562
Amortization of deferred items	1,448	791
Provision for doubtful accounts	1,871	0
Provision for inventory obsolescence	360	435
Deferred income tax benefit	(466)	(425)
Share-based compensation expense	6,813	4,931
Other, net	(13)	863
Changes in assets and liabilities:
Accounts receivable	24,563	(765)
Income tax receivable	(199)	1,764
Inventory	(14,106)	(3,003)
Prepaid expenses	10,109	6,285
Deferred costs and other assets	(8,084)	(14,220)
Accounts payable	(43,864)	10,465
Accrued liabilities	(5,282)	(7,337)
Income tax payable	6,582	4,680
Deferred credits and other liabilities	8,247	(5,441)
Net cash provided by operating activities	204,462	156,288
Cash flows from investing activities:
Capital expenditures	(372,957)	(397,444)
Proceeds from sale of assets	61	0
Net cash used in investing activities	(372,896)	(397,444)
Cash flows from financing activities:
Proceeds from issuance of bonds	0	450,000
Proceeds from bank credit facilities	310,000	80,000
Principal payments on bank credit facilities	(100,000)	(450,000)
Principal payments on notes payable	(5,148)	(5,461)
Proceeds from exercise of stock options	3,418	3,242
Net cash provided by financing activities	208,270	77,781
Net increase (decrease) in cash and cash equivalents	39,836	(163,375)
Cash and cash equivalents, at beginning of period	77,871	295,002
Cash and cash equivalents, at end of period	117,707	131,627
Non-cash activities
Changes in accounts payable and accrued liabilities related to capital expenditures	$ 34,046	$ (65,662)