Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of total capital expenditures incurred to total capital expenditures in the consolidated statements of cash flows
Capital expenditures incurred	$ 92,141	$ 111,325
Additions incurred prior year but paid for in current period	9,465	25,344
Additions incurred but not paid for as of the end of the period	(19,479)	(22,199)
Capital expenditures per Consolidated Condensed Statements of Cash Flows	$ 82,127	$ 114,470