Financial Instruments and Fair Value Measurements (Financial Assets that are Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Financial assets:
Total financial assets	$ 30,345	$ 65,834
Financial liabilities:
Total financial liabilities	63,075	51,387
Cross Currency Interest Rate Swaps [Member]
Financial liabilities:
Cross-currency interest rate swaps	63,075	51,387
Level 1 [Member]
Financial assets:
Total financial assets	30,345	65,834
Level 2 [Member]
Financial liabilities:
Total financial liabilities	63,075	51,387
Level 2 [Member] | Cross Currency Interest Rate Swaps [Member]
Financial liabilities:
Cross-currency interest rate swaps	63,075	51,387
Investments in Term Deposits with Foreign Banks [Member]
Financial assets:
Investments		40,453
Investments in Term Deposits with Foreign Banks [Member] | Level 1 [Member]
Financial assets:
Investments		40,453
Equity Securities [Member]
Financial assets:
Equity securities	30,345	25,381
Equity Securities [Member] | Level 1 [Member]
Financial assets:
Equity securities	$ 30,345	$ 25,381