Financial Instruments and Fair Value Measurements (Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Financial assets:
Total financial assets	$ 42,901	$ 65,834
Financial liabilities:
Total financial liabilities	50,185	51,387
Cross Currency Interest Rate Swaps [Member]
Financial liabilities:
Cross currency interest rate swaps	50,185	51,387
Investments in Term Deposits with Foreign Banks [Member]
Financial assets:
Investments	13,187	40,453
Equity Securities [Member]
Financial assets:
Equity securities	29,714	25,381
Level 1 [Member]
Financial assets:
Total financial assets	42,901	65,834
Level 1 [Member] | Investments in Term Deposits with Foreign Banks [Member]
Financial assets:
Investments	13,187	40,453
Level 1 [Member] | Equity Securities [Member]
Financial assets:
Equity securities	29,714	25,381
Level 2 [Member]
Financial liabilities:
Total financial liabilities	50,185	51,387
Level 2 [Member] | Cross Currency Interest Rate Swaps [Member]
Financial liabilities:
Cross currency interest rate swaps	$ 50,185	$ 51,387