Supplemental Statements of Cash Flows Information (Schedule of Supplemental Statement of Cash Flows Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Supplemental Statement of Cash Flows Information
Interest paid, net of amounts capitalized	$ 39,909	$ 29,677	$ 27,752
Income taxes paid	68,112	44,831	33,926
Income tax refunds received	1,454	1,976	997
Non-cash activities:
Purchases of property, plant and equipment on account	8,737	11,982	17,327
Impact of the adoption of ASC 606 (Note 3)	38,700
Impact of the adoption of ASU 2016-16 (Note 2)	1,005
Common shares issued from treasury stock to settle employee liabilities			1,767
Common shares issued from treasury to settle benefit obligations (Note 20)	$ 14,846	$ 14,741	14,014
Cashless exercise of stock options			$ 1,473