SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Cash payments:
Interest paid, net of amounts capitalized	$ 11,663	$ 5,374	$ 6,991
Income taxes paid	131,128	317,599	363,326
Reconciliation of total capital expenditures incurred to total capital expenditures in the consolidated statements of cash flows
Capital expenditures incurred	1,035,278	1,047,176	791,741
Additions incurred prior year but paid for in current year	123,548	29,264	46,589
Additions incurred but not paid for as of the end of the year	(25,344)	(123,548)	(29,264)
Capital expenditures per Consolidated Condensed Statements of Cash Flows	$ 1,133,482	$ 952,892	$ 809,066