Other (Income) Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Other (Income) Expense, Net
Equity interest in losses (earnings) of the JV (Note 4)	$ (1,006)	$ (382)	$ (1,602)	$ (1,066)
Net (gain) loss on sales of assets	(396)	37	(454)	(3,662)
Rent income	(17)	(70)	(71)	(143)
Net (gain) loss on investments in deferred compensation program	(46)	(705)	(700)	(729)
Other	(148)	(195)	(358)	(303)
Other (income) expense, net	$ (1,613)	$ (1,315)	$ (3,185)	$ (5,903)