Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016
Net accrued retirement benefits, less amounts recognized within accrued liabilities	$ 70,549	$ 70,479
Noncurrent portion of deferred income from JV formation	236,791	238,187
Total unrecognized tax benefits, net of offsetting adjustments	12,541	17,239
Acquired unfavorable contracts	2,859	3,148
Deferred economic incentives	15,685	16,196
Other	13,004	15,573
Other liabilities	358,429	368,224
Loss Reserve On Contractual Lease Commitments [Member]
Loss reserve	$ 7,000	$ 7,402