Other (Income) Expense, Net (Schedule of Other (Income) Expense, Net) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Equity interest in the earnings of the JV (Note 6)		$ (4,681)	$ (3,006)	$ (7,893)	$ (4,471)
Net (gain) loss on sales of assets	[1]	(10)	121	(13,557)	200
Rent income		(324)	(77)	(575)	(144)
Net (gain) loss on investments in deferred compensation program		3,021	(1,656)	1,776	73
Other components of net periodic pension and other postretirement benefit, excluding service cost and interest expense		(2,926)	(3,251)	(5,973)	(6,494)
Other		(143)	(170)	(266)	(382)
Other (income) expense, net		$ (5,063)	$ (8,039)	(26,488)	$ (11,218)
Duarte Facility [Member]
Net (gain) loss on sales of assets				$ (13,522)

[1] Included in net (gain) loss on sale of assets for the six-months ended March 31, 2020 was the pre-tax gain on sale of Duarte real property in the amount of $13,522 recognized in the first quarter of fiscal year 2020.