SUPPLEMENTAL CASH FLOW INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash payments:
Interest paid, net of amounts capitalized	$ 6,991	$ 10,711	$ 16,107
Income taxes paid	363,326	144,959	19,621
Reconciliation of total capital expenditures incurred to total capital expenditures in the consolidated statements of cash flows
Capital expenditures incurred	791,741	1,082,678	730,347
Additions incurred prior year but paid for in current year	46,589	61,591	25,508
Additions incurred but not paid for as of the end of the year	(29,264)	(46,589)	(61,591)
Capital expenditures per Consolidated Statements of Cash Flows	$ 809,066	$ 1,097,680	$ 694,264