Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reconciliation of total capital expenditures incurred to total capital expenditures in the consolidated statements of cash flows
Capital expenditures incurred	$ 169,166	$ 682,435
Additions incurred prior year but paid for in current year	25,344	123,548
Additions incurred but not paid for as of the end of the year	(14,029)	(39,954)
Capital expenditures per Consolidated Condensed Statements of Cash Flows	$ 180,481	$ 766,029