Supplemental Statement of Cash Flows Information (Schedule of Supplemental Statement of Cash Flows Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Information [Abstract]
Interest paid, net of amounts capitalized	$ 27,574	$ 27,148	$ 39,909
Income taxes paid	38,949	94,088	68,112
Income tax refunds received	14,044	17,653	1,454
Non-cash activities:
Purchases of property, plant and equipment on account	7,771	3,076	8,737
Impact of the adoption of ASC 606			38,700
Impact of the adoption of ASC 842		255
Impact of the adoption of ASU 2016-16			1,005
Common shares issued from treasury to settle benefit obligations	14,900	$ 14,748	14,846
Purchases of treasury stock on account	$ 12,516		$ 4,204