Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Other Liabilities [Line Items]
Net accrued retirement benefits, less amounts recognized within accrued liabilities	$ 52,211	$ 70,479
Noncurrent portion of deferred income from JV formation	236,896	238,187
Total unrecognized tax benefits, net of offsetting adjustments	20,949	17,239
Acquired unfavorable contracts	2,076	3,148
Deferred economic incentives	14,574	16,196
Loss reserve	3,927	7,402
Other	14,165	15,573
Other liabilities	344,798	$ 368,224
Loss Reserve On Contractual Lease Commitments [Member]
Other Liabilities [Line Items]
Loss reserve	$ 3,927